The course to take regarding North Korea still hangs on China’s fear that, if North Korea were to collapse economically, a flood of refugees would head for China, diplomats at the UN tell CBS News. But, Falk adds, the fact that China came to the table, again, to impose tougher sanctions, is a reflection of China’s new leadership and an accumulated frustration with North Korea’s intransigence with regard to its nuclear program.” For the last three weeks, the United States, a close ally of South Korea and Japan, has been negotiating the text of a new resolution with China, North Korea’s closest ally. Russian U.N. Ambassador Vitaly Churkin, whose country holds the council presidency this month, told a news conference Monday that a resolution on North Korea might be approved in March, though the text had not yet been circulated. Last month’s statement from the Security Council called the underground test in February a “grave violation” of three U.N. resolutions that ban North Korea from conducting nuclear or missile tests. North Korea’s three nuclear tests — in 2006, 2009 and 2013 — occurred after Pyongyang was condemned by the United Nations for rocket launches. The Security Council imposed sanctions after the first two nuclear tests and after the North’s rocket launch in December, which was viewed as part of the country’s covert program to develop ballistic missiles that can carry nuclear warheads. The sanctions are aimed at trying to derail the country’s rogue nuclear weapons and ballistic missile programs. They bar North Korea from testing or using nuclear or ballistic missile technology, and from importing or exporting material for these programs. The latest sanctions resolution, adopted in January, again demanded that North Korea abandon its nuclear weapons program and cease missile launches. It slapped sanctions on North Korean companies and government agencies, including its space agency and several individuals. The diplomats said they did not know what new sanctions would be included in the resolution to be circulated Tuesday. There has been speculation that a new resolution will strengthen existing sanctions related to North Korea’s nuclear and missile programs, toughen financial restrictions and cargo inspections, and add companies and individuals to the sanctions list. In the meantime, the foreign affairs panels of both houses of Congress this week will consider the Obama administration’s next policy options to impede Pyongyang’s development of missiles and nuclear weapons, which are increasingly viewed as a direct threat to the United States.