The United States has submitted a new North Korean sanctions resolution to the UN Security Council, toning down its demands less than 24 hours before a vote, diplomats say, as it sought to bring China and Russia on board.
Washington has led the international drive to punish the rogue state after it detonated a nuclear device this month.
The US had originally pushed for a strict oil embargo, as well as a freeze on the assets of North Korean leader Kim Jong-Un.
But late Sunday, diplomats said the asset freeze had been dropped from the draft, and it now foresaw a progressive tightening of the oil taps, instead of something sudden and complete.
Among other concessions the new text also softens proposed restrictions on North Koreans working overseas, and on the inspection by force of ships suspected of carrying cargo prohibited by the UN.
Of five key original measures, a ban on textile exports from North Korea remained.
Britain and France -- permanent Security Council members along with the US, China and Russia -- have given Washington their unequivocal backing.
Francois Delattre, the French ambassador to the UN, told AFP: "Maximum pressure today in the form of sanctions is our best hope for promoting a political settlement tomorrow and the best antidote to risks of confrontation."
His British counterpart Matthew Rycroft added: "To give a chance for diplomacy to end this crisis, we need DPRK (North Korea) to change course now. That means the maximum possible pressure."
The sticking point will be opposition from Russia and China, the North's two main backers, who are wary of anything that might force the collapse of the regime and the resulting exodus of refugees.
In addition to bending somewhat to Moscow and Beijing, Washington has dangled the prospect of military action or cutting economic ties with countries that continue to have trade links with the North. Some 90 percent of North Korea's exports are destined for China.
Kim Hyun-Wook, professor at the state-run Korea National Diplomatic Academy, told AFP the Americans had softened their stance because it was vital to keep Moscow and Beijing on board.
"It is only possible to criticise and rebuke China and Russia for not enforcing the sanctions if they vote for it at the UN Security Council," he said.
"That's why I think the US tried to draw a UN sanctions resolution that China and Russia will participate in even if it is not fully satisfactory, which has led to the easing of the initially very strong draft proposal.