"Influential countries gathered around a table, thrashed out an agreement on chemical weapons and put it into practice. They have shown it can be done, so where are the efforts to repeat this success with the burning question of access for humanitarian aid?" said MSF General Director Christopher Stokes in a statement.

The appeal from MSF came four days after the Organization for the Prohibition of Chemical Weapons (OPCW) won the Nobel Peace Prize for its work to rid the world of the devastating weapons.

MSF called for humanitarian aid to be treated as an equally pressing priority.

It said many parts of regions under siege of militant groups are sealed off from aid workers because of the intensity of fighting.

It pointed to the Damascus suburbs of East and West Ghouta, which OPCW inspectors have visited but where MSF said medics report "desperate" drug shortages and cases of malnutrition due to lack of food.

"Syrian people are now presented with the absurd situation of chemical weapons inspectors freely driving through areas in desperate need, while the ambulances, food and drug supplies organized by humanitarian organizations are blocked," said Stokes.

Five million Syrians have fled their homes during the two-and-a-half-year-old conflict.

The kidnapping of seven International Committee of the Red Cross and Red Crescent aid workers in northern Syria at the weekend by militant groups -- four of whom were freed Monday -- has also shone a spotlight on the dangerous conditions facing humanitarian groups.

NJF/NJF