President Barack Obama signed new sanctions on North Korea into law Thursday, punishing the regime for its nuclear and missile tests as well as for suspected cyber-hacking incidents. Congress overwhelmingly passed the measure earlier this month. The two Republican senators running for president, Ted Cruz of Texas and Marco Rubio of Florida, both returned to Washington to vote in favor of the bill. The measure is meant to compel American allies to enact similarly tough restrictions on North Korea to further isolate the country, which conducted its fourth nuclear test in January and recently launched a satellite into space. Tough new multilateral sanctions have been held up at the United Nations Security Council over disagreements between China and other nations. China, a longtime sponsor of North Korea, has expressed concerns about measures that it worries could debilitate North Korea’s economy. Again on Friday, China made its objections clear. “As the situation on the Korean peninsula remains complex and sensitive, all relevant parties should keep calm and restrained, and refrain from doing anything that could escalate tensions,” said Hong Kei, a spokesman for the Chinese Ministry of Foreign Affairs. “We think it is impossible to resolve any hotspot issues through simple sanctions or pressuring.” But South Korea welcomed the American sanctions, with its Ministry of Foreign Affairs saying the new law “shows the strong determination of the U.S. to respond firmly to North Korea’s nuclear test and long-range missile launch.” The unilateral U.S. sanctions Obama approved Thursday would freeze the assets of anyone doing business related to North Korea’s nuclear or weapons programs or is involved in human rights abuses in the country.