Just as the deadly 11 September 2001 terror attacks on the US defined the then president George W Bush's tenure, North Korea will be US President Donald Trump's "September 11", warned a top US expert on Korea.

Victor Cha, a Georgetown University professor and Korea chair at the Center for Strategic and International Studies, also warned that the reclusive state, led by Kim Jong-un, will carry out an intercontinental ballistic missile (ICBM) test or a nuclear test early in the Trump administration.

Cha was addressing a House Foreign Affairs Committee hearing on Tuesday (7 February) where he also said that the Pyongyang regime is delaying the next tests to wait for the ongoing South Korean political turmoil to settle down and for the Trump administration to release its North Korea policy, Yonhap news agency reported.

"Pyongyang carried out two (failed) medium-range ballistic missiles tests prior to President Trump's election on October 15 and 20, 2016. The only reason they have not followed the election with an action, we believe, is because of the domestic political crisis in South Korea," Cha reportedly told the committee.

He added: "However, once this crisis of leadership in the South is resolved (or even before then), ballistic missile and nuclear tests are sure to follow."

Explaining the North Korean regime's penchant for building a strong nuclear arsenal, Cha said that the clear objective behind this weapons drive is "to field a modern nuclear force that has the proven ability to threaten first US territories in the Pacific — including Guam and Hawaii — then the achievement of a capability to reach the US homeland, starting with the West Coast." He added that the ultimate ambition of the communist country is to achieve the ability to hit the US capital, California-based Court House News Service reported.

Cha reportedly called for speeding up the deployment of the Terminal High Altitude Area Defense (Thaad) missile defense system in South Korea and also urged the new US administration to take stringent measures against the North.

At the beginning of the hearing, Ed Royce, chairman of the committee, called for putting greater pressure on the North through tighter sanctions and closing loopholes in existing sanctions. He also warned that "very soon North Korea will be able to target all 50 states, and our allies".

"With hundreds of thousands of North Korean laborers abroad — sending as much as $2bn (£1.6bn) a year back to the regime in hard currency — we should look at targeting this expatriate labor.

"Loopholes in our sanctions on North Korea's shipping and financial sectors must be closed. And when we discover that foreign banks have helped Kim Jong-un skirt sanctions – as those in China have repeatedly done – we must give those banks and businesses a stark choice: do business with Kim Jong-un or the US" he reportedly said.