President Obama on Sunday evening spoke with Chinese President Xi Jinping about the crisis in Ukraine and assured him that he was focused on finding a “peaceful resolution.”

The White House said the two leaders “affirmed their shared interest in reducing tensions and identifying a peaceful resolution to the dispute between Russia and Ukraine.”

“The two leaders agreed on the importance of upholding principles of sovereignty and territorial integrity, both in the context of Ukraine and also for the broader functioning of the international system,” the statement added. “The President noted his overriding objective of restoring Ukraine’s sovereignty and territorial integrity and ensuring the Ukrainian people are able to determine their own future without foreign interference.”

Obama has made a number of calls to fellow leaders as he seeks an end to the standoff between Kiev and Moscow over Ukraine’s Crimean peninsula, which Russian troops seized. On Wednesday, Ukrainian Prime Minister Arseniy Yatsenyuk will visit the White House for talks with Obama.

But there is little sign of a resolution, with Russian President Vladimir Putin ignoring calls to pull back his military forces and the pro-Russian government in Crimea going ahead with plans to hold a referendum on leaving Ukraine.

The U.S. has urged Putin to meet with Kiev's interim government, return military troops to their bases and prevent the referendum.

Obama spoke to the Russian leader twice last week, telling him that the military incursion is a violation of international law.

The president has vowed that Moscow will face “costs” for its actions. Last week, Obama signed an executive order authorizing sanctions and visa bans against individuals found to be “undermining democracy” in Ukraine.

The U.S. and European Union are also offering Ukraine aid to stabilize its economy and help ease pressure from Moscow a major trade partner and energy supplier to Kiev.

Obama has sought to boost U.S. links with China as part of his “pivot to Asia” strategy. First lady Michelle Obama is also scheduled to visit China for a week later this month to promote education ties.