The Kremlin has played down the significance of Trump repositioning US submarines in response to an inflammatory post by Dmitry Medvedev.

Previous Trump promises, threats and cajoling have failed to yield results., and the stubborn diplomatic stalemate will be hard to clear away. Meanwhile, Ukraine is losing more territory on the front line, although there is no sign of a looming collapse of its defenses.

The navies of Russia and China are conducting joint artillery and anti-submarine drills in the Sea of Japan, near the Russian port of Vladivostok, as part of the "Maritime Interaction-2025" exercise, Russian officials said on Sunday.