In a special session of parliament on Kosovo, Chancellor Gerhard Schröder rejected doubts among his government's left-wing minority about the air war and Germany's participation.

"We cannot escape our responsibility," he said. "That is why our soldiers are on their first combat mission since World War II."

German plan

The German proposals on Kosovo were discussed at a brief European Union summit in Brussels on Wednesday.

They provide for:

• A suspension of air strikes if President Milosevic begins withdrawing his forces from Kosovo

• An outright halt once withdrawal is complete

• UN authorisation of an international military force

• A transitional administration for the territory

• Relief agencies start work in Kosovo as soon as possible after a plan is agreed

• Return of refugees and reconstruction

Mr Schöder insisted in his speech that the German plan was in line with Nato's demands and not meant to water them down.

'Ball in Milosevic's court'

But the United States said on Wednesday it would not consider a halt in Nato's bombing campaign against Yugoslavia until all Western demands were accepted.

Mr Schroder still has political backing for Germany's participation

Washington described the German plan as constructive but insisted it could only be implemented after President Milosevic accepted Nato's conditions, with no ceasefire before an agreement.

State Department spokesman James Rubin said the German idea was a way of implementing an agreement, but stressed that the ball was in Mr Milosevic's court.

BBC Correspondent Barney Mason says the Americans are warning their allies against moving too fast rather than rejecting the German ideas out of hand.

Nato said the German proposals were "a useful contribution" to discussion of how "end-game" diplomacy would be handled.

Opposition warning

The EU leaders backed a UN peace initiative for Kosovo that closely resembles Nato's conditions for stopping airstrikes.

Demonstrators protest against German involvement

Wolfgang Schaeuble, head of the main opposition Christian Democrats warned on Thursday that German soldiers must keep out of any Nato ground assault.

German Tornado warplanes are participating in the Nato air operation.

"We cannot allow a creeping expansion of their mission," Mr Schaeuble said.

Nato says it has no intention of a ground war.

A leader of the Greens, Chancellor Schröder's junior coalition partner, acknowledged public concern about the Nato strikes, though polls show most Germans support them.

"We must take fears in the population seriously," said Greens floor leader Rezzo Schlauch. "Many people fear an escalation of violence and wonder when the war will end."