YEREVAN, Armenia — Armenia's new president was sworn into office Monday as the country prepares to transition to a system where the president has far less power.

President Armen Sarkisian promised to work for improvements in the justice system and the fight against corruption.

Armenian voters in 2015 approved changing the government from a presidential system to a parliamentary republic. Under the change, which takes place next month, the presidency will be largely a ceremonial position.

Sarkisian, who served as Armenia's ambassador to Britain, was chosen for the post by members of parliament last month.

Critics say the change in political systems will allow Serzh Sargsyan, who served as president during the past 10 years, to hold on to power in a new role as prime minister.

Sargsyan's party holds a majority in parliament. The next parliamentary election is due in 2022.

Immediately after the new president's inauguration, acting Prime Minister Karen Karapetian announced that Sargsyan would succeed him as prime minister.

"In view of problems and challenges faced by the country, it's very important to ensure a smooth transition to the new system of government," Karapetian said in a statement released by the Cabinet.

The parliament is set to vote on Sargsyan's appointment on April 17.