By Vicki Needham - 06/19/14 11:53 AM EDT
Treasury Secretary Jack Lew on Thursday urged Russia to take quick action to stop the violence in Ukraine or face additional sanctions.
Lew expressed support for Ukrainian President Petro Poroshenko’s efforts to bring peace to the region after months of fighting between Ukrainian troops and pro-Russian separatists.
"We continue to urge Russia to work with Ukraine to reach a negotiated resolution to the current situation,” he said.
"But if Russia is unwilling to reverse course, the United States and the international community is prepared to impose additional cost."
Lew credited Germany for its leadership within the European Union that has helped "maximize pressure on Russia by imposing targeted sanctions" on Russian officials and President Vladimir Putin’s inner circle among others involved in trying to destabilize Ukraine.
Poroshenko, who took office June 7, is planning to unveil a plan that would call for a ceasefire, a point he reiterated in a call with Putin earlier this week.
The plan will be presented to EU ministers early next week.
"Russia must support a peace plan instead of continuing its support for militants and separatists who are further destabilizing the situation instead of allowing the provision of arms and materiel across the border," Lew said.
Meanwhile, heavy fighting continued Thursday between Ukrainian troops and pro-Russian separatists.
On Wednesday, Vice President Biden commended Poroshenko for his commitment to move ahead with his peace plan and take steps to unify the country amid the upheaval.
Biden said that Group of Seven leaders have "clearly called for Russia to stop the flow of weapons and militants across the border and to exercise its influence among the separatists to lay down their weapons and renounce violence, both of which Russia has thus far failed to do."
He said the United States would "work with our partners to impose further costs on Russia if it continued on its current course."
Lew said the international community will provide $27 billion in support for Ukraine.
Meanwhile, Lew said Poroshenko has been clear since he took office that he is committed to finding a peaceful resolution to the crisis, which includes granting amnesty to separatists within Ukraine and providing safe passage back to Russia to those militants operating in eastern Ukraine.
“He also has committed to continue a national dialogue to unite the country and support efforts to decentralize power to address the legitimate concerns of the Ukrainian people," he said.
But to be successful the “separatists must lay down their arms and participate in a political process.”