France, Britain and the United States have asked for an emergency meeting of the U.N. Security Council to press for the lifting of sieges on Syrian cities and towns where some 400,000 people are unable to get humanitarian aid.

France's U.N. mission confirmed that a request for a public meeting was made Thursday to Uruguay, which currently holds the rotating council presidency. It said no date has yet been scheduled.

The request follows this week's delivery of aid to three besieged Syrian towns including Madaya, where the U.N. reported severe malnutrition and people looking like "skeletons."

U.N. Secretary-General Ban Ki-moon and many other officials have called for all sieges in Syria to be lifted.