Ukrainian underwater drones have struck two tankers belonging to Russia’s so-called shadow fleet in the Black Sea, according to an official in Ukraine’s security services (SBU).

Russian President Vladimir Putin appeared last week to be cautiously optimistic on the U.S. 28-point peace plan to end his invasion of Ukraine.

Ukraine has used Sea Baby naval drones to strike two Russian oil tankers in the Black Sea. An official from Ukraine’s security services told The Associated Press about the attack on Saturday.

The two oil tankers, identified as the Kairos and Virat, were empty and sailing to Novorossiysk, a major Russian Black Sea oil terminal.

A Putin ally has called for more detail in Trump's peace plan for Ukraine. Follow Newsweek's live coverage of the war.

Ukraine’s chief negotiator, in an exclusive interview, says conceding sovereign territory is off-limits in peace talks.

In Russia, a major oil terminal near the port of Novorossiysk stopped operations Saturday after a strike by unmanned boats damaged one of its three mooring points, according to a statement from the Caspian Pipeline Consortium, which owns the terminal.

A push by the Trump administration to end Russia's war on Ukraine appears to make headway, with Kyiv saying Zelenskyy could visit D.C. within days to finalize a deal.