Barack Obama: 'This is a joint problem and requires joint effort'
President Barack Obama has urged better use of Nato resources in Afghanistan, saying al-Qaeda is a greater threat to Europe than to the US.
Speaking before a Nato summit co-hosted by France and Germany, he said the US wanted to see a stronger Europe.
However, Nato's secretary general said members would be reluctant to send more troops if Afghanistan adopted a new law seen as violating the rights of women.
A massive French-German security operation is in place for the summit.
The two-day summit marks the 60th anniversary of Nato.
After talks with French President Nicolas Sarkozy on Friday, Mr Obama said they had discussed Afghanistan.
"It's not just a matter of more resources, but more effectively using the resources we have," Mr Obama said.
The US is by far the bigger contributor of international troops in Afghanistan
He thanked France for leadership regarding Afghanistan.
"France recognises that having al-Qaeda operate safe havens that can be used to launch attacks is a threat not just to the United States but to Europe.
"In fact it is probably more likely that al-Qaeda would be able to launch a serious terrorist attack in Europe than in the United States because of proximity.
"This is not an American mission, this is a Nato mission, this is an international mission."
Meanwhile, UK Prime Minister Gordon Brown offered a temporary increase in British troops serving in Afghanistan.
The UK currently has 8,300 soldiers in the country, the second-largest international contingent troops outside the US.
OBAMA'S TRANSATLANTIC VISIT
3 April: Obama meets Sarkozy in France and Merkel in Germany
4 April: Leaders walk across the Rhine and hold North Atlantic Council meeting in Strasbourg
5 April: Obama in Prague for US-EU summit
6-7 April: Obama visits Turkey
On the issue of wider defence, Mr Obama said: "We would like to see Europe have much more robust capabilities."
He added: "We're looking to be partners with Europe, and the more capable they are defensively, the more we can act in concert on the shared challenges we face."
France last month announced it would be fully re-integrated into Nato. For decades it had not been a member of the alliance's military command.
Later, President Obama told an audience in Strasbourg that the US and Europe had allowed the alliance to drift in recent years.
He said the US had been "arrogant" and "dismissive" towards its allies, while there was "insidious" anti-Americanism in Europe. He said these attitudes had to change.
"I've come to Europe this week to renew our partnership - one in which America listens and learns from our friends and allies. But where our friends and allies bear their share of the burden," he said.
Mr Obama also announced a long-term goal of "a world without nuclear weapons", and said he would outline details of his non-proliferation proposal in a speech in Prague on Sunday.
"Even with the Cold War now over, the spread of nuclear weapons or the theft of nuclear material could lead to the extermination of any city on the planet," he said.
Mr Obama went on to Baden-Baden in Germany, where he met Chancellor Angela Merkel.
"Leadership from our two countries is going to be critical" in meeting Nato's future challenges, he said at a joint news conference with Mrs Merkel.
Earlier, Nato Secretary General Jaap de Hoop Scheffer said it could be difficult to persuade European countries to contribute more in Afghanistan because of a planned Afghan law that, among other things, sanctions rape within marriage.
NATO: KEY MOMENTS
Founded 1949, largely to block Soviet expansion into Europe
Twenty-six member states who vow to defend each other
Militarily dominated by the US
Acted in non-member state for first time in 1995 - implementing military aspects of Bosnia peace accord
Operated outside Europe for first time in 2003 - in Afghanistan
He told the BBC: "How can I defend this, and how can the British defend this, when our boys and girls are dying there in defence of universal values, and here is a law that fundamentally violates human rights.
French police were still holding more than 100 of the 300 people arrested on Thursday when masked protesters smashed bus shelters and burned rubbish bins.
Some 25,000 French police are set to patrol protests which could attract tens of thousands of demonstrators.
Several hundred German soldiers are at two sites where activists are expected.
The German towns of Kehl and Baden-Baden are also hosting Nato events for the alliance's 60th-anniversary summit.
At the talks, alliance leaders are expected to consider relations with Russia and possibly announce a new secretary general.
The current secretary general steps down at the end of July. Danish Prime Minister Anders Fogh Rasmussen is regarded as the frontrunner to take over.
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