A group of jurists has petitioned the UN, BBC News revealed Tuesday, demanding that they deliver aid to starving Syrian civilians immediately "with or without consent" from Syria.
The letter, signed by 35 prominent lawmakers, insists that aid is being withheld arbitrarily.
Jared Genser, one of the legal experts who signed the letter, told the BBC that the distribution of UN aid inside the country was unfair.
"What concerns me is that something like 80 to 85% of the aid that's being provided by the UN is going into areas controlled by Assad. And a much lower percentage of it, 15 to 20%, is going into the areas controlled by the rebels," he said. "What we have now in Syria is a situation where you literally have millions and millions of people being denied access to humanitarian aid on arbitrary grounds."
Last week, several UN agency leaders stated that aid missions to the warn-torn countries had failed.
According to the New York Times, the UN now estimates that the three-year conflict has left more than nine million Syrians in need of assistance. Of those, at least 3.5 million are trapped in cities under siege by shifting front lines and artificial famines.
“At least one million people are now in need of urgent humanitarian assistance in Aleppo alone,” the agency heads noted, saying that transportation between the rebel-ruled city and Damascus is virtually unusable and that “other key roads are blocked by different armed forces and groups.”
"The worst days seem yet to come,” they added. “Thus far, diplomatic efforts designed to end years of suffering have failed."
The UN launched a full-scale aid and evacuation mission in Homs in February, which saw at least 1,300 leave in a mass exodus. UN forces themselves came under fire during the aid mission, and aid workers - as well as reporters at the scene - saw residents suffering from severe starvation.
Over 250,000 people are estimated to be in at least 40 blockaded cities across Syria, according to recent estimates - where a national hunger crisis is being used as a political tactic.