"So far the problem has not been fully solved, although there is significant achievement. But there is still some work to be done," Peskov told Russian broadcaster Channel One.
Moscow, Ankara, and the United Nations are making efforts to facilitate the process, according to the spokesman.
On July 22, the deal brokered by Turkey and the United Nations was signed by Ukraine and Russia to unblock shipments of grain, food and fertilizer in the Black Sea despite hostilities. The agreement was initially set to expire on November 19, with a possibility of extension if signatories consent. It was extended for 120 days on November 17.
Russian President Vladimir Putin has repeatedly said that most vessels carrying Ukrainian grain do not reach the world's poorest countries and have ended up in Europe. Putin has also voiced concerns that Russian grain and fertilizer products are not entering the global markets as stipulated by the agreement.