The United States expressed concern about the crisis in Myanmar on Thursday.

WASHINGTON (AFP) - The United States expressed concern about the crisis in Myanmar on Thursday, urging authorities to allow humanitarian access to Rakhine state amid reports of violence against the Rohingya minority.

But the State Department would not say whether Washington is considering sanctions against Myanmar, which is also known as Burma, nor whether US officials find the reports of state-sponsored massacres credible.

"The United States is deeply concerned about the troubling situation in Burma s northern Rakhine state," State Department spokeswoman Heather Nauert told reporters. Rakhine is the country s poorest state.

"There has been a significant displacement of local populations following serious allegations of human rights abuses including mass burnings of Rohingya villages and violence conducted by security forces and also armed civilians," she said.

"We again condemn deadly attacks on Burmese security forces, but join the international community in calling on those forces to prevent further attacks on local populations in ways that are consistent with the rule of law and with full respect for human rights."

The United Nations says that more than 250,000 refugees, most of them Rohingya, have fled Myanmar into Bangladesh since violence erupted last October. Witnesses say entire villages have been burned to the ground since Rohingya militants launched a series of attacks on August 25, prompting a forceful military-led crackdown.

Refugees arriving in already packed camps in Bangladesh, many of them exhausted and desperately hungry, have brought harrowing tales of murder, rape and widespread arson.

"We call on the authorities to facilitate immediate access to affected communities that are in need of urgent humanitarian assistance," Nauert said, adding that US officials are working to help the United Nations cope with the exodus.

But she would not comment on who is at fault in the latest violence. Myanmar s de facto leader, Nobel laureate Aung San Suu Kyi, has claimed that allegations of army-led massacres are part of a "huge iceberg of misinformation" designed to sow division.

Nauert said US diplomats are in regular touch with Myanmar authorities but that Rakhine is "a difficult place to get information from, it s difficult to get access to."

"Some of these areas are areas of open conflict, we can t necessarily get in there," she said. Nauert refused to address calls for international sanctions, saying, "We don t want to get ahead of the conversations that we re having."