"I proposed, in the discussion we had with Olaf Scholz last Saturday, to President Putin that we take the initiative for a resolution at the United Nations to give a very clear framework to this operation," he declared after a European summit in Brussels.

Macron and Scholz called Putin on Saturday, and neither has since referred to a proposed UN resolution, although diplomatic efforts are underway to lift the Russian threat to Odessa, the last major Black Sea port in Ukrainian hands.

Russia's invasion of Ukraine has effectively taken its huge grain harvest off the world market, sending world food prices soaring and threatening to exacerbate humanitarian emergencies in Africa and the Middle East.

The port's Ukrainian defenders have laid mines, and the Russian fleet is preventing cargo traffic from arriving in Ukraine.

Under Macron's proposal, a UN resolution would set up a framework in which the port could be de-mined and grain shipments resume.

Macron paid tribute to UN Secretary General Antonio Guterres's role in searching for a solution and said Russia had been in "promising" talks with its Black Sea neighbour Turkey.

That has led to hopes the situation could be resolved in the "coming days, coming weeks", he said.

"The decision does not depend on us, but it does indeed depend on an agreement from Russia, and guarantees provided by Russia, so that, faced with the de-mining which is essential, security guarantees are provided to the Ukrainians to prevent them from being attacked," he added.