With immediate effect, Russia no longer wants to guarantee the safe passage of Ukrainian grain transports through the Black Sea and is thus once again blocking shipping traffic.

Under a pretext, Moscow is blocking the transports "that mean food security for millions of people," Ukrainian Foreign Minister Dmytro Kuleba wrote on Twitter on Saturday evening.

He was reacting to the suspension announced by Russia in July of an agreement brokered by Turkey and the UN, which ended a month-long war-related blockade of Ukrainian grain exports in the summer.

The grain deal was initially closed for four months until November.

Russia has recently repeatedly criticized the agreement because it sees its own grain exports slowed down by the sanctions imposed by the West in the course of its war against Ukraine.

The Russian leadership sees the United Nations as having a duty to work in the West to ensure that Moscow can also export grain, fertilizer and food and earn money.

That's one of the reasons why Moscow repeatedly threatened to cancel the grain deal.

UN Secretary-General António Guterres described the July agreement as a "beacon of hope" in Russia's war against Ukraine.

He saw the possibility that further steps to resolve the conflict could follow.

Guterres had already called on all sides on Saturday night to make "every effort" to extend the agreement.

The deal was limited to November 18, but could have been automatically extended if neither side had objected, according to the UN.

The United Nations has not yet given up hope that the deal will go ahead.

"We are in contact with the Russian authorities on this matter," said a UN spokesman in New York.

"It is imperative that all sides refrain from any action that jeopardizes the Grains Agreement, which is a crucial humanitarian effort that is clearly having a positive impact on access to food for millions of people worldwide."

Kyiv has so far been silent on Crimean attacks

Russia had previously cited drone attacks against the infrastructure of the Black Sea Fleet in the city of Sevastopol on the Crimean Peninsula, annexed by Moscow in 2014, as the reason for the suspension.

According to the Russian Defense Ministry, the minesweeper Ivan Golubez, which is part of the Black Sea Fleet, was slightly damaged on Saturday.

Regarding the attack in Crimea, the Russian ministry said: "This morning at 4:20 a.m. the Kiev regime carried out a terrorist attack on the ships of the Black Sea Fleet." A total of 16 drones attacked Sevastopol, but most were intercepted.

The information could not be independently verified.

Kyiv initially did not comment on the reports.