Tony Blair has called for the world to "speak with a single voice" in order to exert maximum pressure on Iraq.

Speaking at a press conference following a meeting with his Italian counterpart, Silvio Berlusconi, the UK prime minister defended his hardline stance on Iraq.

He said that it was clear that "without the possibility of force being used the UN inspectors would never have gone back into Iraq at all".

Blair said that a "clear united message on behalf of the world community" was needed to put pressure on Saddam to cooperate fully with the UN inspectors.

"I very much hope that we will speak with a single voice," Blair added.

He said that resolution 1441 demanded full Iraqi cooperation.

"If there is not such cooperation then resolution 1441 makes it clear that Saddam is in breach of the UN will."

Both leaders stood firm in their insistence that war could be necessary to uphold the will of the international community.

"If we cannot disarm him peacefully...are we just going to ignore the issue and hope it will go away?" asked Blair.

"Even now we can avoid conflict, but we cannot avoid it by weakness."

Italy has been a strong supporter of the US approach to dealing with Iraq.

Berlusconi was one of the eight signatories of a controversial article backing the Bush administration.

The Italian leader stressed that countries supporting the US position were not "warlike", but were acting against a dictator.

"It is not that the United States is saying that one must attack tomorrow. One must create military pressure to bring about peace. If you want peace you must prepare for war," he said.

Blair added that the terms and timetable of a second United Nations resolution on Iraq were still being considered.

But he pointed out that Iraq had been reducing cooperating with the UN inspectors over recent days.

Following criticism from senior churchmen, Blair defended the morality of any war.

He told journalists that Saddam would be responsible for any war.

"Does anyone believe he is really cooperating now?" he asked.

"Who is it, therefore, that is responsible for conflict if it comes?

"Us, who have done every single thing we can to solve this peacefully, or him who refuses to abide by the clearly expressed view of the whole of the international conflict?"

The prime minister's defence of the morality of his position came ahead of his meeting with Pope John Paul II on Saturday.

During his visit to the Vatican, Blair is expected to hear pleas for strenuous efforts to avoid war.

Jim Nicholson, American ambassador to the Holy See in Rome, said the Pope had "exactly the position of president Bush" on war in Iraq.

Speaking to the BBC on Friday, he said that both leaders viewed military action as "a last resort".

"The most important thing on the line is the security of innocent people throughout the world," said Nicholson.

"And the president has the responsibility under the catechism of the Catholic Church, not just the right as a duly elected public authority, but the obligation at certain times and in certain conditions to take action to protect innocents."