Donald Trump summons entire US Senate for top-level White House briefing on North Korea

Meeting held at Presidential residence 'to show Pyongyang Washington is serious'

Every US senator has been called to a White House briefing on North Korea, as tensions with the rogue state escalate.

It is unusual for the entire Senate, which has 100 members, to travel to the White House on the same day. They will be briefed by the country's top security officials, including Secretary of State Rex Tillerson, Secretary of Defense Jim Mattis, Director of National Intelligence Dan Coats and General Joseph Dunford, chairman of the Joint Chiefs of Staff, spokesperson Sean Spicer said.

Washington has expressed mounting concern over North Korea's nuclear and missile tests, and its threats to attack the United States and its Asian allies.

Donald Trump triggered speculation he was planning a response in the event of another nuclear test by Pyongyang when he made hastily scheduled calls to Japan’s Prime Minister, Shinzo Abe, and China’s President, Xi Jinping, on Sunday.

Pyongyang had been suspected of planning a new nuclear trial to coincide with the 85th anniversary of the founding of the Korean People's Army on Tuesday.

The isolationist state staged its largest-ever artillery firing drill on Tuesday morning to mark the date, South Korea's Yonhap news agency reported.

On Monday, Mr Trump told UN Security Council ambassadors “the status quo” was not acceptable, saying the council must be ready to impose new sanctions.

Unease has grown around the Korean Peninsula, with the northern state on Saturday arresting a US citizen at Pyongyang airport in an apparent attempt to gain leverage over Washington.

Wednesday's briefing was originally scheduled for a secure room at the Capitol, but Mr Trump suggested a shift to the White House, congressional aides said. They also suggested the briefing was being held at the White House to underscore the message to North Korea that Washington is serious about wanting a shift in policy.

A senior Trump administration official said the flurry of activity around North Korea was “not a part of something choreographed” and cautioned against over-interpretation.

Both Democrats and Republicans welcomed the meeting. “It's (the location) their choice,” said Senator Ben Cardin, lead Democrat on the Senate Foreign Relations Committee. “I hope that we hear their policy as to what their objectives are, and how we can accomplish that hopefully without dropping bombs.”

Republican Senator Lindsey Graham said the administration should be telling senators it had a “red line,” if it has one. “By 2020, if nothing changes inside of North Korea, they'll have the technology, they'll have a breakthrough, to develop an ICBM (intercontinental ballistic missile) that can reach America. I hope this president will say that's a non-starter,” Mr Graham said.

North Korea on Sunday threatened to sink an American aircraft carrier, which had begun joint drills with two Japanese destroyers in the western Pacific Ocean, in a demonstration of its military might.

On Tuesday, a missile-armed US submarine arrived in South Korea, on its way to join the other warships.

The briefing will take place at 3pm local time. Aides said they were working with the White House to schedule a similar briefing for the House of Representatives.

Reuters contributed to this report