Senators arrive at White House for North Korea crisis briefing

The Trump administration is considering placing North Korea on a list of state sponsors of terrorism as  US senators arrived at the White House for an extraordinary briefing on the threat posed by the rogue state.

All 100 senators were invited to a classified briefing at a building next to the White House on Wednesday (US time), reports AFP. They were ferried from Capitol Hill by bus.

President Donald Trump's secretary of state, defence secretary, top general and national intelligence director will brief them. The briefing team was to speak later to members of the House of Representatives lower chamber.

Former US president George W. Bush removed North Korea from the list of state sponsors of terrorism in 2008 but it is understood the Trump administration is now considering placing it back on. 

Though highly unusual, the briefings do not necessarily reflect a security crisis is imminent, although military tensions are rising on the divided Korean Peninsula.

But alarm is rising over North Korea's progress in developing a nuclear-tipped missile that could strike America.

Earlier, a leading US commander told Congress a US missile defence system being established in South Korea to defend against any North Korean attack should be operational in the coming days.

In testimony to the House Armed Services Committee on Wednesday (US time), the top commander in the Asia-Pacific, Admiral Harry Harris, said he is confident the US could defeat any North Korea missile attack on an American aircraft carrier strike group but said commanders should study placing additional missile defence capabilities in Hawaii.