WASHINGTON - Images of violence and refugees from Myanmar's Rakhine state have "shocked the American people and decent people all over the world," US Vice-President Mike Pence told the UN Security Council on Wednesday (Sept 20).

"In recent weeks, the people of my country and the wider world have witnessed a great tragedy unfolding in Burma with the Rohingya people," he said, referring to the Muslim minority in Rakhine state, where reprisals by the Myanmar army in response to militant attacks on Aug 25 have driven over 400,000 across the international border into Bangladesh, spawning an acute humanitarian emergency.

"We see heartbreak and assaults on human rights and innocent civilians that's ultimately endangering the sovereignty and security of the entire region," Mr Pence said in his remarks at a session discussing peacekeeping, during the ongoing UN General Assembly (UNGA).

"Burmese security forces responded to militant attacks on government outposts with terrible savagery - burning villages, driving the Rohingya from their homes," he said.

"And now we're witnessing a historic exodus. Over 400,000 Rohingya - including tens of thousands of children - have now been forced to flee from Burma to Bangladesh, with more following every day."

On Tuesday, US Secretary of State Rex Tillerson called on Myanmar State Councillor Aung San Suu Kyi to urge the Myanmar government and military to facilitate humanitarian aid and confront allegations of human rights abuses.

Referring to a speech by Ms Suu Kyi on Tuesday in Myanmar, he said: "While we welcome Suu Kyi's comments that returning refugees have nothing to fear, the United States renews our call on Burma's security forces to end their violence immediately and support diplomatic efforts for a long-term solution."

Ms Suu Kyi is not attending the UNGA, sending instead one of Myanmar's vice-presidents, Henry van Thio.