President Donald Trump and Russian President Vladimir Putin have concluded a call as the White House pushes its 30-day ceasefire with Ukraine aimed at ending the grinding war.

Trump and Putin agreed during their call to seek a limited ceasefire against energy and infrastructure targets in the Russia-Ukraine war, according to the White House.

The White House described it as the first step in a “movement to peace” it hopes will eventually include a maritime ceasefire in the Black Sea and a full and lasting end to the fighting.

The White House said negotiations would “begin immediately” on those steps. It was not immediately clear whether Ukraine is on board with the phased ceasefire plan.

Putin also called on Trump to end foreign military and intelligence assistance to Ukraine as the U.S. looks to bring an end to Russia’s invasion of Ukraine, according to the Kremlin.