GENEVA (Reuters) - The World Food Programme is considering suspending aid delivery in the areas under the control of Yemen’s Houthi group because of fighting, insecurity and interference it its work, the agency said on Monday.

“Humanitarian workers in Yemen are being denied access to the hungry, aid convoys have been blocked, and local authorities have interfered with food distribution,” the WFP said in a statement. “This has to stop.”

The highly unusual threat from the U.N. agency, which is feeding more than 10 million people across Yemen, reflected what it said were “obstacles that are being put in our way”.

“We face daily challenges due to the unrelenting fighting and insecurity in Yemen. And yet, our greatest challenge does not come from the guns, that are yet to fall silent in this conflict - instead, it is the obstructive and uncooperative role of some of the Houthi leaders in areas under their control.”

The phased suspension of aid would be a last resort and nutrition activities directly targeting malnourished children and women would continue, the statement said.

WFP said it previously worked with leaders to resolve problems, such as when the Saudi-led coalition which is fighting against the Houthis delayed the movement of cranes to the key port of Hodeidah and cut food supplies by blockading the port.

Negotiations with Houthi leaders to open up access to hungry people had not yet brought tangible results, WFP said, although some had made positive commitments.

“Unfortunately, they (Houthi leaders) are being let down by other Houthi leaders who have broken assurances they gave us on stopping food diversions and finally agreeing to a beneficiary identification and biometric registration exercise.”

WFP’s threat of a partial pullout comes after fighting around Hodeidah marred an apparent diplomatic breakthrough by U.N. envoy Martin Griffiths, who got the Iranian-aligned Houthis to agree a unilateral withdrawal of their forces from Hodeidah and two other ports earlier this month.

Since then Houthi fighters and Saudi-backed pro-government forces have battled in the port city, breaching a ceasefire and casting into doubt the full implementation of the plan for both sides’ forces to move back from the port.