Russian President Vladimir Putin demands suspension of all arms supplies to Ukraine during the ceasefire proposed by US President Donald Trump, Bloomberg reports, citing sources.

The two leaders are set to speak by phone on Tuesday about ending the war in Ukraine, with a key objective being the 30-day truce that Kyiv has already said it’s ready to accept. Kremlin spokesman Dmitry Peskov said the call is expected to begin at a time between 15:00 and 17:00 Kyiv time.

The Russian leader, who met with a Trump envoy last week, has made the halt to arms supplies a prerequisite for signing up to the ceasefire, said a senior European official and three people in Moscow familiar with Russia’s position.

While Russia wants to halt all weapons deliveries to Ukraine, the minimum aim is that US aid should stop, said two of the people in Moscow with knowledge of the Kremlin’s thinking.

The senior European official added that Europe was extremely reluctant to agree to Russia’s demand to block deliveries of weapons to Ukraine by its allies during any truce. That outcome would risk a situation where Russia was able to rearm during a cessation of hostilities, while Ukraine was prevented from doing so, the official said.

The Trump administration has effectively already conceded Russian demands to keep control of occupied Ukrainian territory and for Kyiv to abandon its ambition to join the North Atlantic Treaty Organization. That has fueled European concerns that any deal the US president strikes with Putin will leave Ukraine weakened and vulnerable to Russia in the future.