London mayor slams burkini ban ahead of Paris trip
Khan, the first Muslim mayor of a major Western capital, spoke out after some 30 French towns banned the burkini, triggering a fierce debate about women's rights and secularism.
"I don't think anyone should tell women what they can and can't wear. Full stop. It's as simple as that," he told the London Evening Standard newspaper.
"I don't think it's right. I'm not saying we're perfect yet, but one of the joys of London is that we don't simply tolerate difference, we respect it, we embrace it, and we celebrate it."
The highest administrative court in France was on Thursday considering a legal appeal against the ban in one of the towns, Villeneuve-Loubet, near Nice in the south of France.
Khan is due to hold talks with Paris Mayor Anne Hidalgo covering the impact of Britain's vote in June to leave the European Union as well as trade and security.
"I'm here in Paris to make it clear that London is open –open to the world, open to trade, open for new business ventures and collaborations, open to new ideas, new talent and people," Khan said ahead of the visit.
France has been hit by several major attacks in recent months, including in Nice last month when 86 people died after a lorry was driven into crowds of people during celebrations on a national holiday.
The Islamic State [IS] group claimed the attack was conducted by one of its "soldiers".
Investigators have found no proof of driver Mohamed Lahouaiej Bouhlel's allegiance to IS but say he had a fascination with jihad and had planned the attack for months.