TOKYO >> The United States called for a vote Monday on new U.N. sanctions against North Korea, though exactly what measures would be in the resolution remained a mystery.

Security Council diplomats, who weren’t authorized to speak publicly because talks have been private, said the U.S. and China were still negotiating the text late today.

Previous U.N. sanctions resolutions have been negotiated between the United States and China — North Korea’s main trading partner and ally — and have taken weeks, and in some cases months, to finalize.

But the Trump administration adopted a totally new approach with this resolution, presenting its draft to China and all other Security Council members last Tuesday and demanding a vote in six days. Diplomats said China’s U.N. ambassador, Liu Jieyi, who was on a Security Council trip to Ethiopia, flew back to New York on Thursday to take part in negotiations.

North Korea’s Foreign Ministry issued a statement early Monday saying it was watching the United States’ moves closely and warned that it was “ready and willing” to respond with measures of its own. It said the U.S. would pay a heavy price if the sanctions proposed by Washington are adopted.

Ethiopia’s U.N. mission, the current Security Council president, said late today that members would vote on a North Korea resolution following a meeting Monday afternoon on implementing existing sanctions against the Pyongyang government.

The draft circulated by the United States called for imposing the toughest-ever U.N. sanctions on North Korea, including a ban on all oil and natural gas exports to the country and a freeze of all foreign financial assets of the government and its leader, Kim Jong Un.

The U.S. is also seeking to ban all countries from hiring workers from the North and from importing textiles from the northeast Asian nation — two key sources of foreign currency.

In another key measure, the U.S. draft identified nine ships that have carried out activities prohibited by previous U.N. sanctions resolutions. The draft would authorize the 192 other U.N. member states to stop these ships on the high seas to check their cargo without their consent. It would permit the use of “all necessary measures,” which in U.N. language includes force, to carry out an inspection and direct the vessel to a port.

Whether those provisions would remain in any resolution put to a vote Monday remained to be seen.

Beijing and Moscow have called for a resolution that focuses on a political solution and proposed a freeze-for-freeze that would halt North Korean nuclear and missile tests in exchange for the U.S. and South Korea stopping their joint military exercises. That initiative was rejected by the Trump administration.

Russia argues that sanctions aren’t working and President Vladimir Putin expressed concern last week that a total oil cutoff could hurt the North Korean people.

Britain’s U.N. ambassador, Matthew Rycroft, backed the tough U.S. measures and demand for a speedy vote, saying Thursday that “maximum possible pressure” must be exerted on North Korea to change course and give diplomacy a chance to end the crisis.

Professor Joseph DeThomas of Pennsylvania State University, a former U.S. ambassador and State Department official who dealt with North Korea, told The Associated Press on Friday that the U.S. demand for quick council action was “an indicator of how the administration thinks time has run out.”

“My sense is they believe that they don’t have time for a delicate diplomatic dance,” he said. “The other possibility … is they want to see the color of China’s money. They’re putting down the marker here and saying, ‘OK, are you prepared to do what is necessary to put pressure on North Korea at a moment when we’re simply out of time?’”