United Nations Secretary-General Antonio Guterres told Reuters NEXT on Wednesday that it will be difficult to revive a landmark deal that allowed the safe Black Sea export of Ukraine grain, which Russia quit in July over complaints about its own exports.

"It will be difficult. We are going on with our efforts. But it will be difficult," Guterres said.

Guterres said the goal would be to have Russia and Ukraine agree to allow freedom of navigation for each other, but admitted this was unlikely. Russia launched an invasion of Ukraine last year.

The United Nations has blamed Russia's invasion for worsening a global food crisis. Ukraine and Russia are both major grain exporters. Russia also is a big supplier of fertilizer to the world.

U.N. officials are working to try to revive the Black Sea grain deal, which Russia quit a year after it was brokered by the United Nations and Turkey - complaining that its own food and fertilizer exports faced obstacles and that not enough Ukrainian grain was going to countries in need.

While Russian exports of food and fertilizer are not subject to Western sanctions imposed after the invasion, Russia has said restrictions on payments, logistics and insurance have hindered shipments. To convince Russia to agree to the Black Sea deal last year, U.N. officials said they would help facilitate Russian exports.

Ukraine launched what it calls a temporary export corridor in August to allow agricultural exports as an alternative arrangement. More than 700,000 metric tons of grain have left Ukrainian ports via the new route.

Nearly 33 million metric tons of Ukraine grain were exported under the Black Sea deal.

By Alessandra Galloni
Writing by Michelle Nichols; Editing by Will Dunham