Mr Khan said that he hoped the Government understood that on "the issue of public safety and public confidence", he wanted to use the law to enforce face masks in spaces where people were unable to keep social distance.
Although the Government made masks a personal choice in England from July 19, the London mayor kept them as a condition of carriage on Tubes and buses in the capital, a move which was backed by five other Labour regional mayors.
Andy Burnham, the Mayor of Manchester, was among those who supported Mr Khan's decision to extend the requirements for face coverings on buses, trains and trams after July 19.
Mr Burnham described the Government's decision to lift the restrictions as "reckless" and he "strongly encouraged" all commuters in Manchester to continue wearing them on public transport.
Sadiq Khan has said that he wants failing to wear a face mask on the London Underground to be against the law.
The Mayor of London is lobbying the Government to allow Transport for London (TfL) to introduce a new bylaw requiring face coverings to be worn across the city’s public transport network.
This would reset the rules to before so-called Freedom Day on July 19, when face masks were required, and would empower police officers to refuse travel and give out fines to those who decline to wear one but are not exempt.
Mr Khan told the BBC Newscast podcast: "We are trying to lobby the Government to allow us to bring in a bylaw, so it will be the law again, so we can issue fixed penalty notices and we can use the police service and British Transport Police to enforce this."
He argued that enforcing face masks would bolster confidence for commuters and visitors to London's West End, and cited Imperial College London studies showing "not one example" of Covid on surfaces or airflows on the Tube.
"We need people to be coming back to the West End, we want to encourage people to return to their offices. They are not going to do so if they don’t feel public transport is safe," he added.