United States President Barack Obama has warned that Europe is more likely to fall victim to a terror attack than the United States.
Speaking before a Nato summit, Mr Obama said the US wants to see Europe with stronger defences, as it wants to be a partner with rather than a patron to Europe.
"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," said Mr Obama.
"We would like to see Europe have much more robust defence capabilities. That is not something we discourage, we are not looking to be the patron of Europe, we are looking to be partners with Europe," he said.
However, Nato's secretary general said draft Afghanistan laws violated human rights, hindering involvement.
A massive French-German security operation is in place for the summit.
Meanwhile, Nato leaders have failed to agree on a new head for the alliance.
Big European powers had backed Danish prime minister Anders Fogh Rasmussen as secretary general and Germany's Angela Merkel urged leaders to endorse him on Friday.
But Turkey has raised objections - notably over Mr Rasmussen's handling of controversial Danish cartoons depicting the Prophet Muhammad published in 2005.