Turkish President Recep Tayyip Erdogan said Friday he wants to convince his Russian counterpart Vladimir Putin to re-join an agreement on Ukrainian grain exports via the Black Sea, which Moscow declined to renew.

"I think we will be able to ensure the continuation (of the humanitarian corridor) by talking in detail with Mr Putin," Erdogan told media, according to state news agency Anadolu.

The Turkish leader, who called on "Western countries to follow up on Putin's expectations," said he would speak with Putin on the issue after he opposed the extension of an agreement signed in July 2022 in Istanbul with Ukraine under Turkish and United Nations mediation.

Russia has said it is ready to return to the agreement, which has allowed the export of nearly 33 million tonnes of grain from Ukrainian ports, if its demands are met "in their totality".

Moscow says its own deliveries of agricultural products and fertilisers are hampered by Western sanctions.

The two leaders will discuss the grain deal face-to-face in August in Turkey "if (Putin's) visit takes place," he said after twice announcing the Russian president would visit next month.

Russia said Wednesday it now considers ships heading to Ukraine in the Black Sea as "potential military vessels" and their flag countries as parties to the conflict.

The UN on Thursday expressed concern over the "negative effect on global wheat and corn prices which hurts everyone, but especially vulnerable people in the global south".

Erdogan also said that Turkey would "act in accordance with the measures taken by Sweden" that paved the way for Sweden's membership of NATO.

Earlier this month, the Turkish president lifted his veto on Sweden's entry into NATO, saying that the Turkish parliament would ratify the membership when lawmakers return from their summer recess in October at the earliest.