Dubai: The UN Security Council expressed “grave concern” Wednesday that agreements reached four months ago by the warring parties in Yemen have not been carried out and called for their implementation “without delay.”

The council reiterated its endorsement of the December 13 ceasefire agreement between Yemen’s government and Iran-backed Al Houthi militants that called for the “phased but rapid mutual withdrawals” of fighters from the key port of Hodeida, two smaller ports in the province, and Hodeida city.

In their statement, council members “noted with concern continued violence that risks undermining the ceasefire in Hodeida.”

Hodeida is the main international entry point for 70 per cent of imports and humanitarian aid to Yemen, where nearly four years of war have spawned the world’s worst humanitarian crisis.

While the two sides agreed to the redeployment of forces, they have been divided over who will run the port of Hodeida once they pull out. The UN-brokered deal reached in Sweden was vague on that point, saying only that a “local force” would take over without specifying who would lead it.

However, a Saudi-led coalition which backs the Yemeni government, has accused Al Houthis of violating the ceasefire agreement more than a thousand times.

On a positive note, council members welcomed Monday’s announcement by the UN envoy for Yemen, Martin Griffiths, that the government and Houthis had reached agreement on the military plan for the initial redeployment of forces from Hodeida. They urged the rival parties to engage with Griffiths and the head of the UN operation monitoring the withdrawals “to swiftly agree on local security force arrangements” and on the second phase of the redeployment.

The Security Council also called on both parties “to implement the redeployment plans as soon as possible and not seek to exploit the redeployment process.”

The council statement did not single out any party for delaying implementation of the Sweden agreement. But it reaffirmed “their commitment to monitor the parties’ compliance with the redeployment plans.”

Council members also called on the parties “to redouble efforts” to finalise arrangements for a prisoner exchange and to establish a coordinating committee in Taiz, where there has been fighting, as called for in the Sweden agreements.

The council expressed concern about the recent escalation in violence elsewhere in Yemen, notably in Hajjah and on the Yemeni-Saudi border.

A Saudi-led coalition joined the war in 2015 after an Al Houthi coup unseated Yemen’s legitimate government.

Yemeni President Abd Rabbo Mansour Hadi was placed under house arrest but later escaped, setting up temporary government headquarters in the southern city of Aden.

Since then, the coalition was able to win back large swathes of territory from the militants, but main population centers remain under Al Houthi control.

A lightening offensive by Yemeni forces last year was able to liberate much of the Al Houthi-controlled territory along strategic Red Sea, but stopped just short of the Hodeida port, the main conduit for goods and aid.

International pressure was placed on Yemeni forces to pause their assault because of the major humanitarian concerns such a battle would have.

However, the government says Al Houthis are using the port to illegally smuggle in weapons from Iran to sustain their military efforts.

Nonetheless, government forces agreed to a halt their offensive, but reserved their right to resume it if peace talks fail.