"Both sides must immediately return to a humanitarian pause, and most must respect the right of free movement of those civilian men, women and children trapped by the fighting," State Department spokesman Robert Wood said during a news briefing.
Fighting by government and the Liberation Tigers of Tamil Eelam in the Mullaitivu area of Sri Lanka has created dangerous living conditions and a dire humanitarian situation, Wood said.
"The United States calls on the government of Sri Lanka to assist its Tamil citizens by halting shelling of the safe zone, permitting international monitors to ensure the safe exit of the civilians," Wood said.
Further, the government should enforce international humanitarian standards in the refugee camps, grant visas to international aid groups, and allow the monitors and media access to the camps, he said.
"The Sri Lankan government, as legitimate sovereign power, has before it an opportunity to put an end to this lengthy conflict," Wood said. "We urge the Sri Lankan government to employ diplomacy to permit a peaceful outcome of this conflict."
Notable deaths of 2014 [PHOTOS]