Russian President Vladimir Putin asked lawmakers in his country to revoke powers allowing him to use military force in Ukraine, a symbolic step to bolster peace talks between the countries.
Kremlin spokesman Dmitri Peskov said the request was “aimed at normalizing the situation in the eastern regions of Ukraine and comes in response to the launch of trilateral negotiations on this matter," according to The New York Times.
"The president spoke to President Putin and once again urged him to support peace instead of allowing the provision of arms and materiel across the border and continuing support for militants and separatists who are further destabilizing the situation in Ukraine," White House press secretary Josh Earnest said Monday.
Pro-Russian separatists on Monday agreed to a weeklong ceasefire agreement offered by Ukrainian President Petro Poroshenko, ahead of peace talks designed to give the country's southeastern regions greater autonomy.
Talks between rebel leaders, the Organization for Security and Cooperation in Europe, and Kiev were expected on Tuesday.
Poroshenko is also expected to offer amnesty for many separatists as well as safe passage home for Russian fighters who have joined the fight in Ukraine.
The ceasefire, though, could prove fragile, with some attacks continuing through the night and Western leaders raising concerns that weaponry was continuing to flow unabated from Russia into Ukraine.
At an event later Tuesday, Putin said the ceasefire — set to expire Friday morning — should be extended, and called for direct engagement between Ukrainian officials and rebel leaders, according to the Associated Press.
On Monday, Vice President Biden called Poroshenko to discuss the latest developments.
"The Vice President commended President Poroshenko’s leadership in achieving a halt to hostilities and noted the United States would continue to strongly support the additional elements of President Poroshenko’s peace plan," the White House said in a statement.
This story was updated at 12:17 p.m.