The United Nations says it has presented Russia with a set of new proposals in a bid to revive the initiative that had allowed grain exports from Ukrainian ports.

In July, Russia pulled out of the deal brokered by Turkey and the UN, raising concerns about a possible global food crisis.

UN Secretary-General Antonio Guterres told reporters on Thursday that he had sent a letter outlining the proposals to Russian Foreign Minister Sergey Lavrov.

Guterres did not elaborate, but said, "I believe that working seriously, we can have a positive solution for everybody."

Turkish Foreign Minister Hakan Fidan discussed the issue with Lavrov in Moscow on Thursday. Fidan described the proposal package as a "suitable basis for the revival of the initiative."

But Lavrov accused Western nations of impeding a solution of the problems that prevent what he called ''a more active export'' of Russian grain and fertilizers.

The UN's proposals are likely to be on the agenda of a summit between Russian President Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan, which is expected to take place in Russia next week.