The cessation of hostilities was "a glimmer of hope", Syrian President Bashar al-Assad said.
Russia is signing ceasefires with some groups of fighters and assassinating the leaders of others.
The peace deal, which only came into force this weekend, already looks under threat.
The town of Debaltseve came under heavy shelling despite the ceasefire being announced.
The loan necessitates reforms seen as politically toxic by the previous government.
An estimated 13 people per day were being killed in Ukraine, violating the ceasefire agreement signed in September
More than 4,000 people have been killed overall since the separatist rebellions erupted in eastern Ukraine in April
A poll conducted with the help of an ex-Likud strategist shows a majority of Israelis disapprove of the ceasefire
President Petro Poroshenko announced air strikes and artillery assaults on pro-Russian separatists in eastern regions following the end of a ceasefire.