Officials from Russia, Ukraine, Turkey, and the United Nations agreed on key aspects of a plan to resume exports of Ukrainian grain through the Black Sea, senior Turkish and U.N. leaders said, The Wall Street Journal reported.

At a meeting in Istanbul Wednesday, officials from the four parties agreed to establish a coordination center in Istanbul where their representatives would oversee outbound shipments of grain, Turkey’s defense minister said.

During the negotiations, the parties agreed on partial demining and ceasefire, said a person familiar with the talks.

Under the broad agreement reached Wednesday, grain could ship from three Ukrainian ports in convoys escorted by Ukrainian vessels, with a cease-fire to protect vessels within geographical limits and some minesweeping, a person familiar with the talks said.

The Turkish navy would inspect empty ships arriving at Ukrainian ports to address concerns from Russia that the vessels could be used to transport Western arms to Kyiv’s forces. The U.N. will establish a command and control center in Istanbul to monitor threat levels to the shipping.

A person familiar with the talks said an agreement could be signed in the coming days after some technical details are ironed out, but cautioned, “It would be wrong to say an agreement is imminent.”