The U.S. Treasury on Thursday imposed sanctions on a North Korean bank and its China-based representative in the latest step to disrupt Pyongyang's nuclear and missile programs and pressure the government.

The action against Daedong Credit Bank showed that the Obama administration is keeping up pressure on North Korea despite a pause in the threatening rhetoric that followed an atomic test explosion in February and the North's offer this month to negotiate directly with Washington. The U.S. first wants Pyongyang to recommit to abandoning nuclear weapons.

The new sanctions also underscored continuing U.S. concern about North Korean financial institutions and companies operating in China, despite restrictions recently imposed by Beijing on the North's main foreign exchange bank.

“That North Korea's recent bellicose statements and actions seem to have ebbed does not alter the basic facts. North Korea continues to pursue an illicit nuclear and ballistic missile program that threatens the U.S.,” its allies and other countries in East Asia, Undersecretary for Terrorism and Financial Intelligence David Cohen told reporters.

Treasury said that since at least 2007, Daedong Credit Bank has facilitated hundreds of financial transactions worth millions of dollars on behalf of the Korea Mining Development Trading Corporation, Pyongyang's premier arms dealer, and its main financial arm, the Tanchon Commercial Bank.

Kim Chol Sam, the Daedong Credit Bank's Dalian, China-based representative, was also put on the sanctions list, and as well as the bank's front company, DCB Finance Limited, which is registered in the British Virgin Islands and also operates out of China.

Treasury said the designations are a follow-up to the tightening of U.N. sanctions in March that were supported by Beijing _ sign of growing Chinese frustration with its troublesome ally. The newly sanctioned financial institutions are accused of transactions with entities designated by the U.N.

Cohen declined to comment on what China may know about activities of the Daedong Credit Bank and its representative in Dalian _ a northeastern port city, across the Yellow Sea from the North Korean port of Nampo. But he said the U.S. has been communicating regularly with China in recent months on a range of issues related to North Korea's missile and nuclear programs, and will continue to talk to them about the Daedong bank.

“We are hopeful that countries around the world will take notice of what we are doing today and that obviously includes China,” Cohen said.

Following Washington's imposition of sanctions on North Korea's Foreign Trade Bank in March, the leading Chinese state bank shut accounts of the bank. That was seen as a significant step by Beijing, if not sign of a fundamental shift in its policy of supporting Pyongyang, which counts on China for much of its trade, and for food and energy.

Also Thursday, Treasury sanctioned Son Mun San, who it said has directed nuclear-research related efforts at North Korea's General Bureau of Atomic Energy since at least 2010. That organization is responsible for the Nyongbyon Nuclear Research Center and its plutonium research reactor, it said. The reactor has produced fissile material for bombs. (AP)