Ukrainian President Volodymyr Zelenskyy told his country in an address Friday that it could face a pivotal choice between standing up for its sovereign rights and preserving the American support it needs, as leaders discuss a U.S. peace proposal seen as favoring Russia.

Russian President Vladimir Putin, meanwhile, cautiously welcomed the U.S. plan to end the fighting in Ukraine, which contains many of the Kremlin’s longstanding demands while offering limited security guarantees to Ukraine.

The plan foresees Ukraine handing over territory to Russia — something Kyiv has repeatedly ruled out — while reducing the size of its army and blocking its coveted path to NATO membership.

Trump says he wants Ukraine to respond within a week.

Trump said Zelenskyy is going to have to come to terms with the U.S. proposal, and if he doesn't, “they should just keep fighting, I guess.”

Ukrainian officials said they were weighing the U.S. proposals, and Zelenskyy said he expected to talk to Trump about it in coming days.