President Obama will meet next week with Russian President Vladimir Putin during the United Nations General Assembly session, despite frosty relations between the two leaders since Russia annexed the Crimea and Russian-backed forces seized eastern portions of Ukraine.

White House Press Secretary Josh Earnest said that the meeting next week is at Putin’s request and that Ukraine would be at the top of the agenda for Obama. He reiterated that Russian separatist forces in Ukraine were there in a “clear violation  of the territorial integrity of that sovereign nation."

The two leaders last spoke by phone in July after negotiators from Iran and six world powers, including the United States and Russia, reached an agreement to limit Iran's nuclear program. Their last substantive in-person meeting was a 15-minute conversation during the D-Day commemoration in June 2014. (They both attended Group of 20 and Asia Pacific Economic Cooperation meetings last fall.)

The White House issued a statement saying that despite differences in policy, the two leaders needed to discuss Russia's recent military reinforcement of embattled Syrian President Bashar al-Assad and continuing violations of a cease-fire accord for Ukraine that was negotiated by Russian, Ukrainian and European leaders in Minsk, the capital of Belarus.

Earnest said that when they talk about Syria, Obama would encourage Russia to join coalition efforts to combat the Islamic State, but warn that "doubling down on the Assad regime is a losing bet.”  He added that “a face to face sit down seems appropriate at this juncture.”

"Given the situations in Ukraine and Syria, despite our profound differences with Moscow, the president believes that it would be irresponsible not to test whether we can make progress through high-level engagement with the Russians," the White House said. "In particular, our European partners have underscored the importance of a unified message about the necessity of fully implementing the Minsk agreements."

The United States and European nations imposed economic sanctions on Russia after the annexation of the Crimea, and those sanctions are still in effect. They limit investments and dealings with major state-owned companies and prominent individuals.

The White House statement said that Obama "will take advantage of this meeting to discuss Ukraine, and he will be focused on ensuring Moscow lives up to the Minsk commitments. This will be the core message of this bilateral engagement."