Seven more grain ships have left Ukrainian ports under the Black Sea grain deal, the Turkish Defense Ministry said on Tuesday.

"As part of the grain shipment, as of this morning, 7 more ships with grain have left Ukrainian ports," the statement read.

Russia, Ukraine, and Turkey inked an UN-brokered agreement on July 22 to establish a humanitarian maritime corridor for ships transporting food and fertilizer from Black Sea ports.

Three vital Ukrainian ports — Odessa, Chornomorsk, and Yuzhne — have been cleared, allowing exports to restart. The Istanbul-based Joint Coordination Center (JCC) was established to supervise the initiative's operation, including ensuring that cargo ships do not transport illicit commodities or individuals.

Read next: Ukraine sending grain to EU, not developing nations: Putin

According to a JCC study issued on September 12, only 28% of grain shipments from Ukraine have gone to low-income nations, with 44% going to high-income countries.

During the forthcoming SCO conference in Samarkand, Russian President Vladimir Putin said he will discuss a reform of the agreement with his Turkish counterpart Recep Tayyip Erdogan.

Furthermore, the Russian envoy to the UN stated that a portion of the agreement involving Russian food exports was not fully operational, which could lead to the termination of the accords.

Turkey, UN prepare ideas on export of Russian grain to world markets: Diplomatic source

Ankara is working with the UN on procedures to introduce Russian grain to global markets, which are scheduled to be discussed by Turkish and Russian leaders at the upcoming SCO conference in Samarkand, according to a diplomatic source.

"Now, this issue is being worked out by our relevant departments in coordination with the UN. All developed mechanisms and ideas will be presented to the presidents of Turkey and Russia during their scheduled meeting in Samarkand," the source said.

A few days earlier, the sanctions imposed on Russia by the Western countries collectively make dealing with Russian grain difficult, according to United Nations Spokesperson Stephane Dujarric on Friday.

"Miss [Rebeca] Greenspan, on instructions from the Secretary-General back in the spring, was tasked to help iron out this very important initiative because, you know, they are no sanctions on Russia and on Russian fertilizer. But there's a complex situation within the more general sanctions regime that makes trade challenging for the private sector," Dujarric said during a press briefing.

According to the spokesperson, the UN is "working extremely diligently" to ensure that Russian fertilizers reach global markets.

This comes after Russian President Vladimir Putin announced Friday that Russia is ready to export potash fertilizers to developing countries free of charge.