"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 said during a House Foreign Affairs Committee hearing, referring to the North's failed Musudan missile launches.

"That is, President Park Geun-hye's political downfall and the potential for a progressive, pro-DPRK government coming to power in the South has complicated Pyongyang's calculations as they do not want to take actions that might create ballast for the conservatives," he said. "However, once this crisis of leadership in the South is resolved (or even before then), ballistic missile and nuclear tests are sure to follow."

Just as the Sept. 11 attacks defined the term of former President George W. Bush, North Korea is expected to be Trump's Sept. 11, Cha said, adding that he expects the North to carry out an intercontinental ballistic missile test or nuclear test early in the Trump administration.

North Korea has not undertaken any provocative acts since the November election, though leader Kim Jong-un said in his New Year's Day address that the country is close to test-firing an ICBM, an apparent threat that it's perfecting capabilities to strike the continental US. 

The North then placed two ICBMs on mobile launchers for apparent test-firing, but later put those missiles back into hiding. Many experts saw that as a sign that the regime might have opted to wait out until the administration of President Donald Trump puts together its North Korea policy.

In order to cope with the North's threats, Cha said, the US and the South should expedite the planned deployment of the THAAD missile defense system in the South while considering a regular rotation of new strategic assets and capabilities to the peninsula that enhance extended deterrence.

He also said the US should further tighten the screws on Pyongyang, including sanctioning the North's labor exports, which has increasingly become a key source of foreign money for the regime, and considering imposing secondary sanctions.

The Trump administration should also make an early and high-level statement about the North's human rights record and its support of the recommendations of the UN Commission of Inquiry on human rights in the country, the expert said.

"Mobilizing UN Security Council members to implement those recommendations would be an important measure, since North Korea's nuclear program is intertwined with its abuse of its citizens," he said. "A campaign among UN member states to stop the import of North Korean 'slave labor' could arrest millions of dollars of annual income to the regime."

At the start of the hearing, Rep. Ed Royce (R-CA), chairman of the committee, also called for greater pressure on the North, saying the North is close to targeting "all 50 states and our Asian allies with a nuclear warhead."

"With hundreds of thousands of North Korean laborers abroad -- sending as much as $2 billion a year back to the regime in hard currency -- we should look at targeting this expatriate labor," Royce said. 

"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 said.

The chairman also stressed the importance of working closely with South Korea, praising Defense Secretary Jim Mattis for deciding to visit the South in his first overseas trip as secretary. The trip was an "important reminder that our 'ironclad' relationship continues through political transitions," he said. (Yonhap)