United States Secretary of State John Kerry said he clarified in a phone call with Chinese Foreign Minister Wang Yi that China's way to deal with North Korea had failed.

China is the North's major economic and diplomatic backer despite the fact that relations between the two Cold War allies have cooled in recent years. The majority of North Korea's business dealings are with China, which purchased 90 percent of the isolated nation's exports in 2013, as indicated by information compiled by South Korea's International Trade Association.

North Korea completed a nuclear test on Wednesday, although the U.S. government and weapons specialists doubt Pyongyang's affirmation that the device it blasted was an effective hydrogen bomb. The test angered China, which was not given earlier notice. U.S. Republicans and Democrats in the House of Representatives could unite in a rare presentation of solidarity to further fix sanctions on North Korea.

Nancy Pelosi, the House Democratic leader, told journalists that Democrats would support a North Korea bill likely to be brought for a vote by Republicans one week from now. A congressional source said it was expected as soon as Monday. The legislation was passed by the House Foreign Affairs Committee last February, yet it was slowed down until the current week's underground nuclear bomb test.

The House measure would target banks facilitating North Korea's nuclear program and approve freezing of U.S. assets of those directly connected to illicit North Korean activities. It would likewise punish those included in business giving North Korea with hard currency.

It is unclear how more sanctions would stop North Korea, which has paid little notice to universal pressure, as it directed four nuclear tests since 2006 the United States and its associate South Korea are constrained in their military response. A South Korean military official told Reuters that Seoul and Washington had talked about the arrangement of U.S. strategic assets on the separated Korean peninsula, yet declined to give further information.