Syrian regime 'using starvation as weapon of war'
Rejecting the Kremlin claims that attacks on Aleppo have stopped, a US official told AFP "the regime has rejected UN requests to deliver aid to Eastern Aleppo – using starvation as a weapon of war."
The language mirrors the Geneva Conventions' prohibition against starving civilians "as a method of warfare."
Aleppo's quarter of a million residents have been besieged and bombarded for months, prompting international outcry.
Washington is currently weighing further sanctions against Syria and a push for justice at the International Criminal Court in the Hague.
Officials hope that Russian President Vladimir Putin may rethink his country's participation in a war that has seen chemical weapons and barrel bombs used against civilians, if Russia is seen as an international pariah.
|Read also: Syria's chemical weapons: A short history of denial|
Earlier on Friday Russia failed to win re-election to the UN Human Rights Commission, a serious diplomatic blow.
"We are taking steps, whether its ramping up public pressure or other forms of pressure," a second senior Obama administration official told AFP.
"We are still looking at the whole arsenal of tools to make them feel the weight of international criticism, not saying that in and of itself is going to work."
"But we have some indication that they don't want to be viewed – the Russians in particular – as being guilty of war crimes."
"We've also spoken about forms of international accountability when it comes to Russian and regime actions."
The Kremlin said on Friday that Putin did not think it was time to resume airstrikes on Aleppo after the defence ministry requested that a moratorium on bombing be lifted.
Syrian rebels launched a major assault Friday aimed at linking opposition-held districts with the outside world.
But a US official gave the Kremlin's claim short shrift.
"Despite Russia's claims, attacks by the regime and its backers have continued in Aleppo," the official said.
"We continue to look at Russia's actions not their words to determine if Russia is meeting their claims about their military intervention on behalf of the Assad regime."