UNITED NATIONS — The United States and China have agreed to stiffen international financial sanctions against North Korea in a major shift for Beijing, which has long been unwilling to further isolate its intransigent ally.
Whether the development, confirmed Thursday by diplomats at the UN Security Council, means that China will take steps to prevent North Korean ships from bringing coal and iron ore to Chinese ports remains unclear. The United States had pushed for a partial ban on permitting North Korean ships to enter ports around the world.
China is Pyongyang's main economic trading partner — and its principal diplomatic backer. In the past, after previous nuclear tests condemned by the Security Council, China has agreed only to banning weapons transfers and limited sanctions against those linked to the nuclear program.
The draft resolution, which US officials said they intended to circulate Thursday among the 15 members of the Security Council, marks a diplomatic pivot for the Chinese. It seems to have been sparked by North Korea's claim in early January that it had tested its first hydrogen bomb.
US and Chinese diplomats have spent the past two months negotiating the text and pushing for ways to better enforce existing sanctions. That has been the principal challenge with this and other sanctions.
The proposal is likely to come up for a vote in the coming days.
The Americans had initially proposed a long draft measure that, according to one Security Council diplomat, contained many provisions that were never going to fly with Beijing. "It was designed to get the Chinese to sit up and take notice," the diplomat said. "It did that."
Negotiations continued, with the United States eager to win Chinese backing to make sure the new sanctions would be adopted — and not vetoed.
The agreement follows a meeting this week between Secretary of State John Kerry and his Chinese counterpart, Wang Yi, in Washington. On Wednesday, President Obama joined a meeting between Wang and Susan E. Rice, the national security adviser.
The White House said in a statement the two countries "agreed on the importance of a strong and united international response to North Korea's provocations, including through a UN Security Council resolution that goes beyond previous resolutions. They agreed that they will not accept North Korea as a nuclear weapons state."
The draft resolution does not censure North Korea for its human rights violations, which have been painstakingly documented by a UN Commission of Inquiry.