With a police helicopter whirring above and armed officers on patrol, England and France soccer fans were mingling outside Wembley Stadium ahead of what should be an emotionally charged international friendly taking place four days after the deadly attacks in Paris.

The atmosphere was calm on a wet and windy evening in London and there was no sense of panic among supporters, who appear intent on sending a defiant message of unity after at least 129 people died in a string of coordinated attacks in the French capital on Friday.

"Tonight is more about solidarity than football," said 31-year-old England fan Robert Williams, who was wearing a beret and holding a France flag. "It is about remembering the people that have lost their lives in such tragic circumstances."

Prince William and British Prime Minister David Cameron will be among the near-80,000 spectators at English football's national stadium, where there is an increased police presence and enhanced security measures.