"The [Bashar al] Assad regime has cynically allowed limited amounts of aid into Darayya and Muadhamiya but it has failed to deliver the widespread humanitarian access called for by the international community," said UK Foreign Secretary Philip Hammond.
The United Nations humanitarian affairs office says
more than 13.5 million people are in need of assistance due to the crisis in Syria, in which about 250,000 people have been killed.
The organization posted video on Twitter
of a convoy entering the besieged town of Daraya to help civilians there.
A report from a handful of humanitarian agencies last year
concluded that the world is failing the people of Syria.
This year a partial truce was reached, paving the way for the delivery of some aid into parts of the country that desperately needed it.
However, the so-called "cessation of hostilities"
has significantly disintegrated, in turn making humanitarian assistance delivery more difficult.
The opposition's chief negotiator, Mohammad Alloush, resigned this week over
the failure of the peace talks, saying the international community had failed to stop the Assad regime's atrocities.
"What we have said all along is we want them [the Syrian regime] to support sustained, complete, comprehensive, unimpeded access of humanitarian assistance," said State Department spokesman John Kirby.
"They have not met that expectation, consistently have not met that expectation. And to the degree that they have hindered it, limited it, allowed it to get tantalizingly close to people in need and then pull it back or pull parts of it back, clearly, it shows at the very least a lack of concern for their own citizens and a willingness to spit in the face of the international community as the international community continues to push for that delivery."
As part of an agreement reached about two weeks ago, parties trying to negotiate a peace deal in Syria said they would call upon the World Food Program to conduct air drops to deliver aid to those in need.
However, that's a process that's not as effective as ground deliveries, in which "you can get the most stuff there to where it's needed and in the quantity that's required and more expeditiously, more -- frankly, more directly," Kirby says.