MOSCOW, Russia - The Kremlin said on Friday President Vladimir Putin will discuss with Turkish President Recep Tayyip Erdogan a landmark deal allowing grain exports from Ukraine that Russia has repeatedly criticised.

The agreement between Russia and Ukraine, which was brokered by Turkey and the United Nations in July, designated three ports for Kyiv to send much-needed grain supplies through a Russian blockade.

But Russia has voiced increasing criticism of the deal, saying its own exports have suffered. Putin this week claimed most of the consignments were arriving in Europe, not poor countries where grain was needed most.

Ukrainian officials have denied the claim and data compiled by a monitoring group as part of the accord does not reflect Putin's assertion.

Kremlin spokesman Dmitry Peskov told reporters on Friday that a meeting between the leaders over the deal was "possible and necessary".

"A conversation between Putin and Erdogan is already being prepared and, as we are hoping, will take place in Samarkand," Peskov said, referring to a regional summit in Uzbekistan next week.

"This conversation is much needed."

Ukraine and Russia are two of the world's biggest exporters of wheat and other grains, and the blockade of Kyiv's ports raised global prices and fears of severe shortages.

Russian Deputy Foreign Minister Andrey Rudenko told reporters on Friday that any extension of the deal beyond its deadline in November would depend on "how all aspects are implemented".

"Unfortunately, it's not being implemented quite as planned," he said.

"The second part of the deal, namely exports of Russian grains and fertilisers, unfortunately still faces difficulties," he said, according to comments carried by Russian news agencies.