Ukraine is not ready to agree to a plan to export its grain by rail across Belarus for shipment via the Baltic Sea to bypass Russia’s blockade of its Black Sea ports, President Volodymyr Zelenskiy said on Monday.

Zelenskiy told a news conference in the capital Kyiv that there could be as much as 75 million tonnes of grain stuck in Ukraine this autumn.

Belarus, used by its ally Russia as a staging ground for Moscow’s Feb. 24 invasion, has said it is ready to let Ukrainian grain go via the country to Baltic Sea ports, if Belarus is allowed to ship its goods from the ports as well.

Russian President Vladimir Putin, who says Moscow is carrying out a special military operation in Ukraine, has also touted the idea as a solution.

“We are not yet ready to follow this format and help our ‘friendly’ neighbours,” Zelenskiy was quoted as saying by Interfax Ukraine.

Zelenskiy told reporters that Ukraine had discussed with Britain and Turkey the idea of a navy from a third country guaranteeing safe passage of Ukraine’s grain exports through the Black Sea.

However, he said the strongest guarantee of their safe passage would be with Ukrainian weaponry.

“Our strongest guarantee of unblocking this or that corridor from ports for the export of grain is to respond with weapons that will be located in the region,” he told reporters.

“We are working on this with specific states, with specific anti-ship systems, we are working and are gradually receiving them,” he said.