LONDON - French President Nicolas Sarkozy pledged to send more troops to Afghanistan under the right conditions as he arrived in Britain Wednesday for a two-day state visit aimed at creating a new era of trust between the neighbouring countries.

Sarkozy said in an interview in advance of his arrival that France and Britain must work together on defence, immigration and the economy.

The French president is making the first state visit to Britain by a French president in 12 years. During the 36-hour trip he will be a guest of the Queen at Windsor Castle, hold talks with British Prime Minister Gordon Brown and address members of both Houses of Parliament.

In an interview broadcast Wednesday, Sarkozy said France is committed to winning in Afghanistan and that he is willing to send more troops to the country if France's allies are also ready to stay, give Afghans more responsibility and better co-ordinate non-military efforts.

"Can we afford to lose in Afghanistan?'' Sarkozy told British Broadcasting Corp. "Of course not. In Afghanistan, what is at stake is part of our battle against world terrorism.''

Canada has said it will pull its 2,500 troops out of Afghanistan if other allies do not offer more help. Canada wants 1,000 more troops for anti-Taliban efforts in the southern province of Kandahar.

"If all the terms and conditions are met, why not send in more troops?'' Sarkozy said in the radio interview recorded in Paris on Tuesday. He is expected to brief Brown about details of France's plans when they meet on Thursday.

Sarkozy also stressed his admiration for what he called British strength and dynamism, calling for "a new Franco-British brotherhood.''

"It has been long enough now that we have not been at war, that we are not wrangling,'' he told the BBC. "Perhaps we can move from being cordial to being friendly -- that's my first message.''

The agenda for Sarkozy's meetings Thursday with Brown includes a number of weighty topics: expansion of France's military role in NATO and Afghanistan, a possible joint nuclear energy program, immigration and the credit crisis that has spread from the United States to Europe.

Prince Charles and his wife Camilla greeted Sarkozy and his glamorous wife, the model-turned-singer Carla Bruni-Sarkozy, as they landed Wednesday morning at London's Heathrow Airport. They will receive a formal welcome from the Queen and Prince Philip on the outskirts of Windsor before enjoying a carriage ride to the castle.

After visiting the Queen, Sarkozy and Bruni-Sarkozy will lay a wreath at the Tomb of the Unknown Warrior at Westminster Abbey -- a gesture designed to emphasize the two world wars Britain and France have fought together -- and the president will give a speech to Parliament.

Sarkozy will attend a state banquet later Wednesday at Windsor Castle hosted by the Queen and said he expects guests to be impressed by his ceremonial outfit.

His focus Thursday will be meetings with Brown at the British prime minister's official residence in Downing Street.

In an interview appearing Wednesday in France's Le Monde daily, Brown said that France and Britain could work together on projects including reforms of the United Nations, the World Bank and the International Monetary Fund. He suggested the World Bank could be transformed into a bank financing environmental and development projects, while the IMF could become a financial crisis alert system.

A host of French and British ministers will join the leaders for a summit at London's Emirates Stadium, home of the popular Arsenal soccer club, an English team with a French manager and some top French players.

Ministers plan to use the meetings to thrash out thorny issues including slow progress on a joint call for a 26,000-strong peacekeeping unit of UN and African Union troops for Sudan's western Darfur region and new support for French language lessons in British schools.