Nato faces a crisis on Monday over contingency plans for fighting a war with Iraq.

It is inexcusable on the part of those countries Colin Powell US Secretary of State

One or more members strongly opposed to war with Iraq appear almost certain to block a US request to beef-up fellow member Turkey's defences.

Under the alliance's "silent procedure" the request will go through if no member formally objects by Monday's deadline of 0900 GMT - but Belgium has said it will use its veto, possibly with French support.

Top US officials have said that such a move would be "shameful" and "inexcusable".

The BBC's correspondent in Brussels, Stephen Sackur, says that the rift between the US and what Mr Rumsfeld has called "old Europe" threatens to do lasting damage to Nato solidarity.

US request

"We are going to block it [the US request] between now and Monday - it is settled," Belgian Foreign Minister Louis Michel said on Sunday.

He was speaking after a bruising weekend of talks between US Defence Secretary Donald Rumsfeld and Western European allies.

Mr Michel added: "When one has to take a slap in the face such as the insulting remarks... by Mr Rumsfeld who comes to teach a thing or two to 'old Europe' - the Europe of democratic values, humanist Europe, the Europe of the Age of Enlightenment - personally I find that this hurts."

Belgium, France and Germany have been objecting to the US request to help Turkey - which shares a border with Iraq - for three weeks.

The military package for Turkey, requested by Washington on 15 January, includes:

• Patriot anti-missile batteries
• Awacs surveillance planes
• Chemical and biological protection units

'Peace undermined'

While Germany appeared to indicate at the weekend that it might relent, France seems to be maintaining its opposition along with Belgium.

The three states argue that making preparations to defend Turkey could undermine diplomatic efforts to avert war.

At the same time, France and Germany have mooted a new plan of their own for resolving the Iraq crisis peacefully, by boosting UN weapons inspectors already on the ground there.

Their proposals have been backed by Russian President Vladimir Putin.

If a veto is lodged on Monday, Turkey could respond by invoking Article Four of Nato's founding treaty, which calls on the alliance to consult whenever a member state feels its territory is threatened.

Correspondents say the move would be unprecedented.

Correspondents say Turkey could also by-pass Nato as a body and seek the support of individual members. Diplomats say this would spell the collapse of the alliance.

'Shameful'

US Secretary of State Colin Powell said on Sunday that he could not understand how any of Nato's 19 members would veto support for Turkey.

"I think it is inexcusable on the part of those countries and I hope they will think differently by the time they have to make a judgment tomorrow," he told America's Fox News.

His indignation was echoed by Mr Rumsfeld in an interview for Italy's La Repubblica newspaper.

"For me it's truly shameful," he was quoted as saying. "Turkey is an ally. An ally that is risking everything... How can you refuse it help?"

The stage is set for a furious behind-the-scenes row at Nato headquarters, our correspondent says.