The governments of Yemen, Saudi Arabia and the United Arab Emirates are accusing Houthi Shiite rebels of breaking the cease-fire in Yemen's key port of Hodeida and refusing to withdraw their forces in accordance with a December agreement.

Ambassadors from the three countries urged the U.N. Security Council in a letter circulated Tuesday to call on the Houthis to implement the agreement reached in Stockholm and to condemn their continuing violations of the cease-fire.

The coalition countries accused the Houthis of refusing to withdraw from two smaller ports of Salif and Ras Issa as called for in the agreement, and of reinforcing their military positions in civilian areas of Hodeida, including by constructing trenches and barriers.

They said their discipline and restraint "has not been reciprocated by the Houthis."