European Union (EU) leaders issued a fresh joint appeal to U.S. President Donald Trump on Ukraine, imploring him ahead of his crunch summit with Russian President Vladimir Putin in Alaska on Friday, August 15.

Kyiv and its European allies fear Trump will consent to the concession of Ukrainian territory Moscow has seized during its invasion, which they say will reward Russia for its unlawful aggression and signal that it could take similar action elsewhere.

Twenty-six EU leaders—Hungary being the only member state that did not want to co-sign—said in the statement Tuesday that they welcomed Trump’s efforts to end Russia’s invasion and seek “a just and lasting peace and security for Ukraine”.

But they warned: “A just and lasting peace that brings stability and security must respect international law, including the principles of independence, sovereignty, territorial integrity and that international borders must not be changed by force.

“The people of Ukraine must have the freedom to decide their future. The path to peace in Ukraine cannot be decided without Ukraine. Meaningful negotiations can only take place in the context of a ceasefire or reduction of hostilities.

“Russia’s war of aggression against Ukraine has wider implications for European and international security. We share the conviction that a diplomatic solution must protect Ukraine’s and Europe’s vital security interests.”

This is a developing article. Updates to follow.