The Russian leader said that his country had agreed to the deal’s extension several times not in Ukraine’s interests, but for its allies in Africa and South America.

Russia endorsed the deal “to support developing countries — our friends, and in order to achieve the lifting of sanctions from our agricultural sector”, Putin said. “We have been deceived once again. We are now thinking about how we can get out of this so-called grain deal.”

Russia has threatened repeatedly to leave the agreement, which was brokered by the United Nations and Turkey last year and extended for two months in mid-May. Even with Russia’s involvement, traffic to Ukraine’s ports has been disrupted, with Ukraine accusing Russia of slow-walking checks and blocking ships destined for one of the three ports in the deal.

Russia and Ukraine are both major agricultural exporters, and mixed messages over the fate of the deal have contributed to volatility in grain prices. In May, total agricultural shipments through the safe corridor hit the lowest since it was agreed, according to UkrAgroConsult.

Wheat traded in Chicago held earlier gains after Putin’s comments, trading up 1.1%.