BRUSSELS (Reuters) - EU countries have formally adopted a plan to use windfall profits from Russian central bank assets frozen in the EU for Ukraine's defence, the Belgian government said on Tuesday.

The text only needed a rubber-stamp by ministers after EU ambassadors reached the agreement in early May.

Under the agreement, 90% of the proceeds will go into an EU-run fund for military aid for Ukraine, with the other 10% going to support Kyiv in other ways.

The EU expects the assets to yield about 15-20 billion euros ($16.30-$21.70 billion) in profits by 2027. Ukraine is expected to receive the first tranche in July, EU diplomats said.

The Group of Seven countries (G7) froze around $300 billion worth of Russian financial assets soon after Moscow's invasion of Ukraine in 2022. Since then, the EU and other G7 countries have debated how and whether to use the funds to help Ukraine.

U.S. Treasury Secretary Janet Yellen is pushing fellow G7 nations this week to agree a plan to use the profits as collateral to back a larger loan to help Ukraine.

($1 = 0.9204 euros)

(Reporting by Julia Payne; Editing by Ros Russell)