Khan arrived in the country's commercial capital as part of his first official tour to three Indian cities, others being Delhi and Amritsar, to strengthen the UK capital's trade ties.
"I am a big critic of the British government over the change in the Visa policy. I think they have made a big mistake, as on one hand the British government is asking Indian businesses to trade there and on the other hand they have made it more hard (to enter the country)," Khan said during his interaction with reporters.
Recently, the Theresa May government changed its visa policy for non-EU (European Union) nationals to curb its soaring immigration figures. The policy which came into effect in November will affect a large number of Indians, especially IT professionals.
"I want to assure you that I am lobbying with my government to change its immigration stance, because I want talented Indians to come to London and not go to Canada, Australia or the US. London is open to people, talent and partnership," the London Mayor said.
India last month flagged its serious concerns to Britain over its stringent visa norms and hike in threshold limit of annual pay of working professionals to get the travel documents.
Khan said the change in UK's current position on immigration is needed in the interest of the UK capital.
"One of the reasons why London is the greatest city in the world is its ability to catch talent. (A total of) 40 per cent of Londoners are from outside the UK. IT's in the interest of London to change its stance on immigration and I'm optimistic that it will change in near future," he said.
The visiting Mayor also underlined the need to forge strong cultural ties with India, particularly with Mumbai.
Hailing Bollywood, Khan said they wanted to learn how the industry can churn out so many movies in a year.
"One thing that we are doing in Mumbai is learning how you mange to make so many films in Bollywood..what is that you are doing? Indian films' post-production work is excellent.
Hollywood filmmakers come here to do their post production work. So, one of the announcements we are making tomorrow will be of the UK and India making films together, which will be a good example," he said.
Khan said students will benefit a lot as professionals after they get education in the top universities in London.
"There are more international students in London than any other city in the world. Four of the world's top 30 universities are in London. Due to the change in the visa policy, some Indian students chose to go to Canada or Australia.
"However, I want to tell Indian students that our universities are brilliant. When you come to London, apart from fantastic quality of education you get, you also get the experience and the contacts you make...This will stand you in good head when you return to (your) country as executive, investor, teacher or entrepreneur," he said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)