Outgoing German Foreign Minister Annalena Baerbock on Tuesday called on US President Donald Trump not to force Ukraine into a peace agreement with Russia, after Moscow unilaterally announced a three-day truce for early May.

"It cannot be in the interests of one of the world's biggest players, the US, either, to conclude a deal, a pact, that leads to further aggression," Baerbock said on the sidelines of a meeting on ramping up defence in the Baltic region on Denmark's Bornholm island.

Ministers from the Nordic-Baltic Eight (NB8), along with counterparts from Germany, Poland, and France, are meeting in Bornholm to discuss security and cooperation in the Baltic Sea.

"We need a reliable, lasting peace," Baerbock said, adding that this was what the Europeans stand for.