By Rick Fountain BBC correspondent in London

Russia has now formally said that it cannot accept the latest American draft resolution on Iraq in the United Nations Security Council.

Iraq denies developing weapons of mass destruction

The statement from the Russian Foreign Minister, Igor Ivanov, in Moscow, came almost in the same hour that the White House warned it could not wait forever for the Security Council to agree.

Earlier the French Foreign Minister, Dominique de Villepin, said that much work remained to be done.

And the chief UN weapons inspector, Hans Blix, said after talks with Mr Ivanov in Moscow that the five permanent members of the Council were still "some days" from reaching agreement.

Deadlock

It is unusual, in this post-Cold War period, for the Security Council's permanent members to be so completely at loggerheads.

The US could ask the UN to take over in Iraq

The Council prefers consensus and yet, after weeks of talks, the US and Britain are still far apart from the other three permanent members, China, France and Russia.

The explanation has to be that, however bad the present regime in Baghdad, nothing much has changed or come to light that makes a global call to arms now urgent and irresistible.

It has been believed for years that Iraq was again dabbling in weapons of mass destruction, but it was thought the threat it posed could only be a local one, and that to attack Israel would be to invite annihilation.

Deadlock in the Security Council will not mean the Americans give up thoughts of independent military action, but that path promises many obstacles.

Regime change

To invade a sovereign country and overthrow its leader without UN authority is a serious breach of international law.

Washington could, of course, then ask the UN to take over in postwar Iraq but the outcome might not be what it had fought for.

To keep in power a credible and reliable new leader - if one could be found - would require much money and a long-term military commitment.

And the other option, to impose, as some western newspapers have hinted, a US military governor, would be an arrangement embarrassing to America's friends.