SHANGHAI — It is gold or bust for U.S. as the two-time defending World Cup champions try to become the first nation to win three straight.

Serbia, Spain and Greece are among the top teams that won't make it easy for the Americans.

The tournament starts Saturday and there will be two teams advancing from each group to the round of 16, which begins on Sept. 6. Quarterfinal play starts Sept. 10, semifinals are on Sept. 13 and the championship game is in Beijing on Sept. 15.

Capsule previews for the eight groups:

___

GROUP A

Schedule:

At Beijing

Aug. 31: Poland vs. Venezuela, Ivory Coast vs. China

Sept. 2: Venezuela vs. Ivory Coast, China vs. Poland

Sept. 4: Ivory Coast vs. Poland, Venezuela vs. China

Teams:

CHINA

FIBA ranking: 30.

NBA fans already know names like Yi Jianlian and Zhou Qi, but Guo Ailun — a 25-year-old with almost a decade of national-team experience already — might end up being the biggest key to the hosts' potential World Cup success.

IVORY COAST

FIBA ranking: 64.

Deon Thompson was part of North Carolina's 2009 NCAA championship club, and has a silver medal from the 2007 FIBA U-19 world championship (where he played for the U.S. on a team with Stephen Curry, Patrick Beveley, DeAndre Jordan, Michael Beasley and more).

POLAND

FIBA ranking: 25.

Poland coach Mike Taylor is a Florida resident who once served as the assistant coach for Nick Nurse — now coach of the NBA champion Toronto Raptors and Team Canada — with the G League's Rio Grande Valley Vipers.

VENEZUELA

FIBA ranking: 20.

Gregory Vargas averaged 11.3 points, 4.3 rebounds and 2.7 assists for Venezuela in the 12-game series of World Cup qualifiers, and is one of eight returnees from the team that played in the 2016 Rio Olympics.

THE PICKS

China and Poland to the second round.

___

GROUP B

Schedule:

At Wuhan, China

Aug. 31: Russia vs. Nigeria, Argentina vs. Korea

Sept. 2: Nigeria vs. Argentina, Korea vs. Russia

Sept. 4: Korea vs. Nigeria, Russia vs. Argentina

Teams:

ARGENTINA

FIBA ranking: 5.

The seemingly ageless 39-year-old Luis Scola is in his fifth World Cup, and has been part of Argentina winning 15 medals in major international competitions over the last two decades. An early concern — top guard Facundo Campazzo is dealing with a sprained right ankle.

KOREA

FIBA ranking: 32.

Dimunitive guard Heo Hoon is the youngest on the Korean roster at 24, though has a legacy already — his father, Hur Jae, is a Korean player and coaching legend.

NIGERIA

FIBA ranking: 33.

One of the few teams in the tournament that could have five NBA players on the court at one time if it wanted, with Ike Diogu, Al-Farouq Amini, Ekpe Udoh, Josh Okogie and Chimezie Metu all on the final roster.

RUSSIA

FIBA ranking: 10.

Russia was one of the last teams to finalize a 12-man roster for the World Cup, and will likely rely on shooting guard Sergey Karasev in the group stage.

THE PICKS

Argentina and Nigeria to the second round.

___

GROUP C

Schedule:

At Guangzhou, China

Aug. 31: Iran vs. Puerto Rico, Spain vs. Tunisia

Sept. 2: Tunisia vs. Iran, Puerto Rico vs. Spain

Sept. 4: Puerto Rico vs. Tunisia, Spain vs. Iran

Teams:

IRAN

FIBA ranking: 27.

Former NBA player Hamed Haddadi provides veteran presence, and the player to watch might be streak-shooting guard Mohammad Jamshidi — a real 3-point threat who also has the ability to score in traffic.

PUERTO RICO

FIBA ranking: 16.

The opening game against Iran is a must-win for Puerto Rico, a team that added undrafted Sacramento Kings signee Isaiah Pineiro — whose grandparents are Puerto Rican — to the national roster for the first time this summer.

SPAIN

FIBA ranking: 2.

Gold-medal hopefuls with Marc Gasol, Ricky Rubio and Sergio Llull leading the way for a very veteran squad. Spain should have minimal trouble getting to the second round.

TUNISIA

FIBA ranking: 51.

Dallas center Salah Mejri is the leader for Tunisia, along with California-born wing Michael Roll — who was part of three Final Four teams at UCLA and became a Tunisian citizen in 2015.

THE PICKS

Spain and Puerto Rico to the second round.

___

GROUP D

Schedule:

At Foshan, China

Aug. 31: Angola vs. Serbia, Philippines vs. Italy

Sept. 2: Italy vs. Angola, Serbia vs. Philippines

Sept. 4: Angola vs. Philippines, Italy vs. Serbia

Teams:

ANGOLA

FIBA ranking: 39.

Angola coach Will Voigt is a native of Vermont, coached Nigeria at the 2016 Olympics — and not only used to work in the San Antonio Spurs' video room, but crashed at the home of Spurs coach (and Team USA coach) Gregg Popovich for a few months when he needed a place to stay.

ITALY

FIBA ranking: 13.

Marco Belinelli and Danilo Gallinari lead the way for the Italians, who stumbled into the tournament with seven losses in their final eight tuneup games this summer — including a 32-point routing from Serbia.

PHILIPPINES

FIBA ranking: 31.

The name people will best know is naturalized Filipino and nine-year NBA veteran Andray Blatche, but the name they should know is June Mar Fajardo — a 6-foot-11 center with five MVP awards from his homeland's top pro league.

SERBIA

FIBA ranking: 4.

The roster is loaded: All-NBA center Nikola Jokic, Boban Marjanovic, Nemanja Bjelica and Bogdan Bogdanovic are all on the team, which has made clear that it believes it can win the gold medal.

THE PICKS

Serbia and Italy to the second round.

___

GROUP E

Schedule:

At Shanghai

Sept. 1: Turkey vs. Japan, Czech Republic vs. U.S.

Sept. 3: Japan vs. Czech Republic, U.S. vs. Turkey

Sept. 5: Turkey vs. Czech Republic, U.S. vs. Japan

Teams:

CZECH REPUBLIC

FIBA ranking: 24.

Tomas Satoransky's best scoring game for the Washington Wizards last season was a 21-point effort on Jan. 27 — at San Antonio. He'll lead the Czechs, who open against the U.S. and Spurs coach Gregg Popovich.

JAPAN

FIBA ranking: 48.

Wizards rookie and Gonzaga alum Rui Hachimura and Memphis forward Yuta Watanabe (who went to high school in Connecticut and played college ball at George Washington) are the clear leaders of this squad.

TURKEY

FIBA ranking: 17.

There's plenty of talent there, with NBA players Cedi Osman, Ersan Ilyasova and Furkan Korkmaz leading the way for a team that went to the quarterfinals of the last World Cup in 2014.

UNITED STATES

FIBA ranking: 1.

It's gold or bust for the two-time defending World Cup champions, bidding to become the first nation to win three straight. Kemba Walker and Donovan Mitchell could be a dynamic backcourt, but the loss to Australia last week raised plenty of eyebrows — and doubt.

THE PICKS

The U.S. and Turkey to the second round.

___

GROUP F

Schedule:

At Nanjing, China

Sept. 1: New Zealand vs. Brazil, Greece vs. Montenegro

Sept. 3: Montenegro vs. New Zealand, Brazil vs. Greece

Sept. 5: Brazil vs. Montenegro, Greece vs. New Zealand

Teams:

BRAZIL

FIBA ranking: 12.

Anderson Varejao, Leandro Barbosa, Cristiano Felicio and Alex Garcia lead the way for the Brazilians, who beat Montenegro earlier this summer and might have to do it again in the group-play finale to advance.

GREECE

FIBA ranking: 8.

NBA MVP Giannis Antetokounmpo of the Milwaukee Bucks leads the Greeks, and has said he would give back that trophy in exchange for World Cup gold. Florida-born point guard Nick Calathes — a former Florida Gator — will run the offense.

MONTENEGRO

FIBA ranking: 28.

Orlando Magic star Nikola Vucevic, coming off the best season of his NBA career, gives his homeland hope of a second-round berth — but the opener against Greece will be daunting.

NEW ZEALAND

FIBA ranking: 38.

The player to watch may be guard Tai Webster, who was a big-time scorer for Nebraska as a senior there in 2016-17 and went on to get a summer league stint with the Golden State Warriors.

THE PICKS

Greece and Brazil to the second round.

___

GROUP G

At Shenzhen, China

Schedule:

Sept. 1: Dominican Republic vs. Jordan, France vs. Germany

Sept. 3: Germany vs. Dominican Republic, Jordan vs. France

Sept. 5: Germany vs. Jordan, Dominican Republic vs. France

Teams:

DOMINICAN REPUBLIC

FIBA ranking: 18.

Dominican Republic coach Nestor Che Garcia has also led the national teams of Uruguay, his native Argentina and Venezuela — plus has coached pro teams in Puerto Rico, Argentina, Saudi Arabia, Venezuela, Uruguay, Mexico and Spain.

FRANCE

FIBA ranking: 3.

A very real gold-medal contender led by Rudy Gobert in the middle, returning All-World Cup team member Nicolas Batum and NBA veterans Evan Fournier and Nando De Colo. Frank Ntilikina will get minutes at point guard.

GERMANY

FIBA ranking: 22.

Dennis Schroder and Maxi Kleber figure to be the two leaders for the Germans, coached by former North Carolina guard Henrik Rodl. The game against the Dominican Republic could be make-or-break for Germany.

JORDAN

FIBA ranking: 49.

Jordan was a very tough out when it debuted at the World Cup in 2010, losing by one to Australia (a game where it led by five with just over a minute remaining) and nine to Argentina.

THE PICKS

France and Germany to the second round.

___

GROUP H

Schedule:

At Dongguan, China

Sept. 1: Canada vs. Australia, Senegal vs. Lithuania

Sept. 3: Australia vs. Senegal, Lithuania vs. Canada

Sept. 5: Canada vs. Senegal, Lithuania vs. Australia

Teams:

AUSTRALIA

FIBA ranking: 11.

The Boomers pulled off the pre-tournament shock with a win in Melbourne over the United States, and arrive in China with plenty of momentum. Patty Mills runs the offense, and Andrew Bogut patrols the paint.

CANADA

FIBA ranking: 23.

Not having Miami's Kelly Olynyk (knee) will hurt the Canadians, who are still good enough for the second round but will have to survive what will likely be the best of the eight groups. Nick Nurse, coach of the NBA champion Toronto Raptors, is coaching Canada.

LITHUANIA

FIBA ranking: 6.

Memphis' Jonas Valanciunas and Indiana's Domantas Sabonis are the two best players for the Lithuanians, who bring back five players from the team that went to the World Cup in 2014.

SENEGAL

FIBA ranking: 37.

Senegal went 10-2 in the African Qualifiers for the World Cup, tying Nigeria and Tunisia for the best record. But it'll be a tall task for Senegal to break through in this group.

THE PICKS

Australia and Lithuania to the second round.