Since it first emerged that Michael Flynn had repeated phone conversations last December with Russia's ambassador to the United States, one of the most significant unanswered questions has been what transition team officials and Donald Trump, then the president-elect, knew about the calls. The documents made public ­Friday show that the transition team knew that Flynn was going to be discussing sanctions with then Ambassador Sergey Kislyak and raise new questions about what Trump knew about the conversations. Here are some key dates around the conversation and the subsequent fallout that offer insight into what the transition team knew at the time:

Dec. 29, 2016

On the same day that President Barack Obama announced new sanctions against Russia in retaliation for interference in the 2016 election, Flynn called a senior member of the presidential transition team who was with other members of the team at Trump's Mar-a-Lago resort. Flynn and the senior transition official discussed what Flynn should relay to Kislyak about the new sanctions and what effect they could have on Trump's foreign policy agenda. "Immediately" after his call with the senior transition official, Flynn called Kislyak, according to court documents made public Friday. Flynn told the ambassador that Russia should not retaliate in response to the sanctions. In a subsequent call, Kislyak told Flynn that "Russia had chosen to moderate its response to those sanctions as a result of his request."

Dec. 30, 2016

The following day, President Vladimir Putin of Russia announced that Moscow would not retaliate against the United States for its latest round of sanctions, surprising some in the Obama administration who had expected an aggressive response from Putin.

In response to Putin's announcement, Trump praised the Russian ­president.

Jan. 15, 2017

Mike Pence, the vice president-elect who was the head of the transition team, has said repeatedly that he did not know that Flynn had discussed sanctions on the calls with Kislyak. Pence gave an interview to CBS News.

Feb. 9, 2017

The Washington Post reported that Flynn had indeed discussed sanctions with the ambassador. In the days after that story, Pence read a transcript of at least one of the calls and saw that Flynn had misled him, according to lawyers briefed on the investigation.

Feb. 13, 2017

Trump fired Flynn.

Feb. 14, 2017

The following day, Sean Spicer, the White House spokesman, said that Flynn had been fired for misleading Pence and other officials about what transpired on the phone calls with Kislyak. "We've been reviewing and evaluating this issue with respect to General Flynn on a daily basis for a few weeks, trying to ascertain the truth," he said. "We got to a point not based on a legal issue, but based on a trust issue, where a level of trust between the president and General Flynn had eroded to the point where he felt he had to make a change. The president was very concerned that General Flynn had misled the vice president and others."

New York Times