The United States on Friday stunned other members of the UN Security Council by preventing a vote on a resolution for a ceasefire in various conflicts around the world to help troubled nations better fight the coronavirus pandemic, diplomats said.

Washington's reversal came a day after it agreed to the text, negotiators said under cover of anonymity.

"The United States cannot support the current draft," the country's delegation declared, without further detail, to the 14 other Security Council members, after nearly two months of difficult negotiation over the text. The latest stalemate continues to leave the global peace and security body largely mute in the face of a once-in-a-century pandemic that has killed more tha 270,000 people and raised further fears for the world's most vulnerable.

When asked for an explanation of the US move, a State Department official told AFP that China had "repeatedly blocked compromises that would have allowed the Council to move forward."

Diplomats told AFP that the language used in the draft to describe the World Health Organization was behind the US move to prevent the vote. But other sources said Washington wanted the Council to return to an initial draft of the resolution which highlighted the need for "transparency" in global cooperation in tackling the pandemic.

"In our view, the Council should either proceed with a resolution limited to support for a ceasefire, or a broadened resolution that fully addresses the need for renewed member state commitment to transparency and accountability in the context of COVID-19," the State Department official said.

US President Donald Trump has accused the WHO of downplaying the seriousness of the outbreak in China.

The procedure blocked by the United States would have allowed the sponsors of the resolution, France and Tunisia, to put it to a vote.