Germany, France, Russia and Ukraine agreed on Saturday to use their influence to implement a ceasefire and the withdrawal of heavy weapons from Monday in eastern Ukraine.

Fighting has recently escalated between Ukrainian forces and Russian-backed separatists in the region, refocusing global attention on a simmering conflict that has strained relations between Russia and the West.

“On Feb. 20 the ceasefire regime will start and withdrawal of heavy military hardware will also start,” Russian Foreign Minister Sergei Lavrov said after talks with his Ukrainian, German and French counterparts in Munich.

The Minsk peace agreement, brokered by France and Germany and signed by Russia and Ukraine in February 2015, calls for a ceasefire, the withdrawal of heavy weapons from the front line and constitutional reform to give eastern Ukraine more autonomy.

But since the deal the sides appear stuck in a stalemate broken periodically by sharp resurgences of fighting that Kiev and the Kremlin accuse each other of instigating.

Since the end of January, shelling on both sides of the front line near the government-held town of Avdiyivka has been heavier than at any time since last summer.

“All parties will use their influence to implement the agreement of the trilateral contact group from Feb 15,” German Foreign Minister Sigmar Gabriel told reporters, referring to a body comprising Ukraine, Russia and the Organization for Security and Cooperation in Europe (OSCE).

“The aim is to have a ceasefire starting from Feb. 20 and to do what has long been agreed but never implemented: To withdraw the heavy weapons from the region, to secure them and enable the OSCE monitors to control where they are kept.”

U.S. President Donald Trump’s new administration has said that any sanctions imposed on Moscow following its annexation of Crimea and events in eastern Ukraine would not be lifted until there was progress on implementing the accords.

Speaking to Reuters after the meeting, Ukrainian Foreign Minister Pavlo Klimkin said he was “not at all” happy and lamented a lack of “powerful results.”

Echoing those comments, Lavrov said there had been a lack of results, but that he believed Ukraine and rebels would abide by the Feb. 20 date.

Despite their differences, French Foreign Minister Jean-Marc Ayrault said neither Moscow nor Kiev had offered any alternatives to the Minsk process.

“The meeting showed that Russians and Ukrainians had no other option, but to respect Minsk. They have no alternatives. We agree to meet quickly, perhaps in three weeks, to see if we can advance on the ceasefire, withdrawal of heavy weapons and exchange of prisoners. We need a lot of patience, because we can see a lack of will on either side.”