The US and Japan have insisted a UN Security Council vote on a resolution condemning North Korea's recent missile launches should be held on Saturday.
China has indicated it will veto the draft resolution
The US envoy to the UN, John Bolton, said the draft did not have to include a reference to Chapter Seven of the UN Charter, allowing for the use of force.
The resolution would still, he said, be legally binding.
China has said it will veto any resolution that contains a reference to Chapter Seven.
"My instructions are to get a vote by tomorrow [Saturday]," John Bolton told reporters on Friday.
Japan's UN ambassador, Kenzo Oshima, said: "Japan stands on the same ground."
"There are many, many occasions when the council has to take very difficult decisions and I think this is one of those very, very difficult decisions," he added.
'Too many fires'
Japan has long been seen as the Asian nation with the toughest stance on North Korea.
It produced its draft resolution for the 15-member Security Council just days after North Korea test-fired seven missiles - including a long-range Taepodong-2, a weapon which is believed to be capable of reaching Alaska.
But China, Russia and South Korea believe punitive action is not necessary, and China's ambassador to the UN, Wang Guangya, confirmed on Thursday he had been instructed to veto Japan's resolution at the Security Council.
A rival Chinese-Russian draft eliminates mandatory sanctions, and requests rather than demands that UN member states try to prevent material that could be used in missiles from getting to North Korea.
"The important thing is not the deadline, it is the unity of the council," said Mr Wang.
"There are too many fires there. We don't need to put oil on all those fires," he added, in an apparent reference to the Middle East crisis and the row over Iran's nuclear plans.