The U.S. Senate Foreign Relations Committee unanimously passed a strong sanctions bill on North Korea on Thursday, demonstrating bipartisan support for a tough response to the communist nation's fourth nuclear test.

The legislation, which combined two similar bills proposed respectively by Sens. Cory Gardner (R-CO) and Robert Menendez (D-NJ), calls for mandatory blacklisting of those assisting Pyongyang over its nuclear and missile programs, human rights abuses, cyberattacks and other crimes.

Calls for the bills' passage gained bipartisan traction after the North stunned the world with a surprise nuclear test on Jan. 6 that it claimed involved a hydrogen bomb, a sophisticated nuclear weapon with yields much greater than conventional ones.

The House overwhelmingly passed its own sanctions legislation on the North a week after the nuclear test.

"North Korea's fourth nuclear test earlier this month marks the third nuclear test to take place during the Obama administration, providing further evidence that Pyongyang's capabilities are growing and reaffirming that we can no longer afford to turn a blind eye to the North Korean threat," Gardner said in a statement.

The legislation "imposes broad, mandatory sanctions on the North Korean regime in order to apply the pressure required to change North Korea's pattern of illicit activities that have gone unchecked for too long," the senator said.

The bill centers on imposing mandatory sanctions on those who contribute to the North's nuclear program and proliferation activities, cyberattacks or the regime's continued human rights abuses.

In particular, the legislation targets not only banned and illicit activities, such as money laundering, counterfeiting and drug trafficking, but it also targets Pyongyang's trade in minerals and precious metals, a key source of hard currency for the country.

"If those (minerals and metals) are being used for the purpose of either funding or supplying the proliferation activity that is sanctioned by the bill, then that would create not only sanctions on North Korea but also second-order sanctions around the globe,"

Gardner said in an interview with Yonhap News Agency last week.

Menendez said that regardless of the truth of the North's H-bomb claims, the test represents "another alarming step forward in its nuclear program and merits a firm response."

"Whether it is nuclear proliferation, cyberattacks or human rights violations committed against its own people, North Korea's regime -- and now its trading partners -- will know that the United States will not stand for it," he said.

"We've taken an important step today, but the enactment of this bipartisan legislation would represent the most meaningful and comprehensive response toward addressing the threat that North Korea presents to our national security interests and the security interests of our friends and allies," he said.

The South Korean government hailed the Senate panel's move, expecting the bill to be approved at its plenary session in February.

It took note of the stipulation on sanctioning entities and individuals transferring major minerals such as coal and steel in connection with WMD activities.

In that sense, it's a "tough" measure against the North, the Foreign Ministry said.

The Senate committee's unanimous action shows a consensus in the U.S. on the need for a strong response to North Korea's fourth nuclear test, added the ministry. (Yonhap)