US President Donald Trump has said the United Nations Security Council must impose new sanctions on North Korea, amid escalating tensions between Washington and Pyongyang.

Trump made the remarks while speaking to reporters on Monday ahead of a lunch with ambassadors from countries on the Security Council.

"The status quo in North Korea is also unacceptable and the council must be prepared to impose additional and stronger sanctions on North Korean nuclear and ballistic missile programs," the US president said.

"This is a real threat to the world, whether we want to talk about it or not. North Korea is a big world problem and it's a problem that we have to finally solve," he added.

Last week, the Security Council threatened to impose tougher sanctions on North Korea in return for its “highly destabilizing” actions.

The council said on Thursday that Pyongyang’s tests of nuclear-capable missiles and nuclear activities "are greatly increasing tension in the region and beyond."

It also expressed "utmost concern" at Pyongyang's "highly destabilizing behavior and flagrant and provocative defiance" of six previous UN sanctions resolutions.

North Korea has so far conducted five confirmed nuclear tests and numerous missile test-launches. While it has not fired missiles against other countries, it has vowed strong action -- including missile attacks against South Korea -- if it is invaded by the South and the US.

North Korea has threatened the US with “all-out war” and announced that Pyongyang would continue to test missiles on a weekly basis.

The US has been unnerved by North Korea’s advancing missile and nuclear programs and has dispatched a military strike group to the Korean Peninsula. North Korea has threatened to sink the American aircraft carrier USS Carl Vinson that President Trump is sending to the western Pacific Ocean.

"Our revolutionary forces are combat-ready to sink a US nuclear powered aircraft carrier with a single strike," North Korea's ruling Workers' Party newspaper said in a commentary on Sunday.

The article said Pyongyang had weaponry that “can reach continental US and Asia Pacific region.”