Armenia's President Armen Sarkissian announced his resignation on Sunday, according to a statement posted on his official website.

"I thought for a very long time and have decided to resign after four years of active work as president," Sarkissian said in a statement, which added that "the president does not have the necessary tools to influence the important processes of foreign and domestic policy in difficult times for the people and the country."

He also noted that some political groups have been targeting him and his family, without giving further details.

"I hope that eventually the constitutional changes will be implemented and the next president and presidential administration will be able to operate in a more balanced environment," the statement added.

Sarkissian was in a standoff with Prime Minister Nikol Pashinian last year over a number of issues, including the dismissal of the head of the armed forces following the defeat at Nagorno-Karabakh.

He had even called on Pashinian to step down.

He described Pashinian's signing of a cease-fire agreement with Azerbaijan on the Nagorno-Karabakh issue and the withdrawal of Armenians from Karabakh as a "great tragedy."

"There is a solution in any country where such a great tragedy has occurred. The government that led to this has to go," he said.

Sarkissian had previously said he was not involved in the process of signing a peace deal between Armenia and Azerbaijan that ended the decadeslong Nagorno-Karabakh crisis.

Armenia has also recently been involved in efforts to normalize relations with Turkey.

Bilateral relations between the two countries have gained a new dimension toward normalization recently, with Turkish and Armenian special envoys scheduled to meet in Moscow on Jan. 14 to lead dialogue between Ankara and Yerevan.

Turkey was one of the first countries to recognize Armenia’s independence on Sept. 21, 1991 after the collapse of the Soviet Union.

It sent humanitarian aid to Armenia, which was struggling with serious economic problems after declaring its independence, and helped Yerevan integrate with regional organizations, the international community and Western institutions. The bilateral relations deteriorated after Armenia’s occupation of Nagorno-Karabakh, internationally recognized as Azerbaijani territory.

Turkey ended direct trade with Armenia in 1993 and the border between the two countries was closed.

Armenia's economy has struggled since the Soviet collapse and money sent home by Armenians abroad has aided the construction of schools, churches and other infrastructure projects, including in Nagorno-Karabakh.