BUCHAREST, April 1, 2008 (AFP) - US President George W. Bush arrived in Romania Tuesday ready to back Ukraine and Georgia's bid to join NATO in the face of French concern that it would upset the balance of power in Europe.

According to excerpts of remarks he will make to NATO leaders at their summit here late Wednesday, Bush is also set to urge them to 'finish the fight' in Afghanistan, where the alliance is struggling against a Taliban insurgency.

On a stop-over in Kiev, on his way to NATO's biggest ever gathering, Bush said Washington wanted to see former Soviet republics Ukraine and Georgia given a Membership Action Plan (MAP) -- a formal step to joining NATO.

'I strongly believe that Ukraine and Georgia should be given MAP and there's no trade-offs, period,' Bush told reporters, alongside Ukrainian President Viktor Yushchenko.

'My position is absolutely solid. Ukraine and Georgia should be given MAP.'

Bush said he had been assured by every NATO nation that Russia 'won't have a veto' on the issue at the summit, but a tirade against it is expected from President Vladimir Putin, altbeit after a final decision is announced.

But French Prime Minister Francois Fillon disagreed.

'We are opposed to the entry of Georgia and Ukraine because we think that it is not a good answer to the balance of power within Europe and between Europe and Russia,' he said.

'France has a different view from the United States,' he told France Inter radio, in the first public remarks against the two by a government since German Chancellor Angela Merkel opposed their membership last month.

Almost a dozen NATO countries are thought to be opposed, fearing that bringing the two countries closer could destabilise, rather than stabilise, the region.

'We want to have a dialogue with Russia on this,' Fillon said.

Nonetheless Yushchenko voiced confidence that Ukraine would be given the go-ahead in Bucharest, even as Russian officials warned that any future membership would undermine European security.

'Admission of Ukraine into NATO will lead to a deep crisis in Russian-Ukrainian relations,' Russian Deputy Foreign Minister Grigory Karasin was quoted by Russian news agencies as saying.

'This affects pan-European security.'

More to Washington's liking was Fillon's announcement that France could send 'several hundred' extra soldiers to Afghanistan following demands by US Defence Secretary Robert Gates for NATO members to contribute more personnel.

NATO commanders have called for the NATO-led force there, which numbers some 47,000 troops drawn from 40 nations, to be bolstered by 10,000 additional personnel, especially in the south and east near the Pakistan border.

'If we were to let up the pressure, the extremists would re-establish safe havens across the country, and use them to terrorize the Afghan people and threaten our own,' Bush is to say, according to his prepared remarks.

'Our alliance must maintain its resolve and finish the fight in Afghanistan,' the remarks said, as Washington pressed fellow NATO members to step up their troop commitments, with some reluctant to deploy to dangerous areas.

'Just two weeks ago, Osama bin Laden issued an audio recording in which he threatened Europe with new attacks. We need to take the words of the enemy seriously,' he said.

Looking to weekend talks in the Black Sea resort of Sochi with Putin, who firmly opposes US plans to plant elements of a missile defence system in Europe, the US president warned: 'The need for missile defense in Europe is real and it is urgent.'

Bush said Washington was working on defences against short-, medium-, and long-range missile strikes and declared: 'As we do, we are inviting Russia to join us in this cooperative effort to defend Russia, Europe, and the United States against an emerging threat that could affect us all.'

He said he would tell Putin 'that the missile defense capabilities we are developing are not designed to defend against Russia just as the new NATO we are building is not designed to defend against Russia. The Cold War is over.'