The U.N. aid chief says efforts will continue in the coming days to extend a deal allowing the safe Black Sea export of Ukraine grain.

It’s a pact Russia has threatened to quit effective Thursday over obstacles to its grain and fertilizer exports.

The final two ships are due to leave Ukrainian ports today under the Black Sea deal.

The U.N. and Turkey brokered the Black Sea agreement last July to help tackle a global food crisis that has been aggravated by Moscow’s invasion of Ukraine, one of the world’s leading grain exporters.

At the same time, the U.N. agreed to help Moscow facilitate its own agricultural shipments.

A Ukrainian foreign ministry official said on Monday that no additional talks were planned this week.