The United States has no other choice at this time but to ratchet up pressure on North Korea, which has repeatedly defied international obligations, the State Department said Monday.

The department, however, strongly indicated its intention to continue engaging Pyongyang either bilaterally or multilaterally, looking for signs that the nation will change its attitude.

 "What's left to us is to continue to increase the pressure on the North Korean regime," department spokeswoman Victoria Nuland said at a press briefing.

She was answering questions on whether the Obama administration will consider shifting its approach toward Pyongyang, which is armed with nuclear weapons and apparently emboldened by the success of its long-range rocket launch last week.

"We're looking at how best to do that both bilaterally and with our partners going forward," Nuland said. "Until they get the message, we're going to have to continue to further isolate this regime."

She said the U.S. is still in consultations with the other members of the dormant six-way talks. The other members are South Korea, China, Russia and Japan.

"Nobody, not we, not anybody in the six- party talks, wants to reward the DPRK (North Korea) for violating its international obligations," she said, adding the U.S. wants a "willing partner" for dialogue. (Yonhap News)