US backs calls for Syria ceasefire

The United States has supported calls for a humanitarian ceasefire in Syria to bring relief to civilians.

White House Press secretary Jay Carney said basic humanitarian supplies are very scarce as a result of "reprehensible actions taken by the Assad regime".

The Red Cross is in talks with Syrian Authorities in an effort to bring about a daily two-hour halt in the fighting to allow it to deliver vital aid, and bring out the sick and wounded.

The Syrian army has pummeled residential areas of the city of Homs for days in a campaign to crush opponents of Assad's leadership.

Rights groups estimate more than 6,000d people have been killed in the crackdown since last March.