Ukrainian President Volodymyr Zelenskyy says the bridge linking Russian-annexed Crimea Peninsula to Russia is a military target.

Zelenskyy told the Aspen Security Forum in the United States, which he attended online, that the bridge that was damaged by explosions on Monday was "not just a logistical road".

He said, "This is the route used to feed the war with ammunition, and it militarizes the Crimean Peninsula."

Zelenskyy was apparently responding to Russian President Vladimir Putin's assertion that the bridge had not been used for military purposes for a long time.

Russia blamed Ukraine for the attack on the bridge, and responded by firing missiles on Ukraine's port city of Odesa facing the Black Sea, where grain is loaded for export.

It also practiced firing anti-ship cruise missiles in the Black Sea. These moves are apparently aimed at keeping Ukraine and Western nations in check.

Russia announced on Monday that it was withdrawing from a deal to allow grain exports from Ukrainian ports.

The Institute for the Study of War, a US think tank, says Russia's withdrawal from the deal is likely part of the Kremlin's efforts to extract concessions from the West to lift sanctions, which Putin has made a condition for returning to the deal.