The White House said on Sunday that the United States and Ukraine drafted an "updated and refined" peace framework during talks in Geneva, Switzerland.

Both sides agreed to continue to work on joint proposals in the coming days, according to a joint statement released by the White House. And final decisions under this framework will be made by the presidents of Ukraine and the United States.

The statement also noted that Ukraine expressed its gratitude to the United States and to U.S. President Donald Trump.

Earlier on Sunday, Trump lashed out at Ukraine in a social media post, accusing its leaders of being ungrateful. "Ukraine's leadership has expressed zero gratitude for our efforts," he wrote.

Representatives from the United States, Ukraine and European countries met in Geneva on Sunday as the White House pushes for agreement on a 28-point plan to end the Ukraine crisis.

Following a meeting between the Ukrainian delegation and national security advisers from Britain, France and Germany, the Ukrainian side held bilateral talks with the U.S. representatives.