Frustrated US lawmakers called on Tuesday for a high-powered response to North Korea’s nuclear tests, saying Washington should act alone if necessary to stiffen sanctions on companies from China, Russia and any country doing business with Pyongyang, Reuters reports. “I believe the response from the United States and our allies should be supercharged,” said Representative Ed Royce, chairman of the House of Representatives Foreign Affairs Committee. “We need to use every ounce of leverage… to put maximum pressure on this rogue regime,” the Republican congressman told a hearing on North Korea. “Time is running out.” The UN Security Council stepped up sanctions on Monday following Pyongyang’s sixth nuclear test on Sept. 3, imposing a ban on textile exports and capping oil imports. It was the ninth sanctions resolution unanimously adopted by the council since 2006 over North Korea’s ballistic missile and nuclear programs. To win Chinese and Russian support, Washington dropped demands including a bid for an oil embargo.