Not one American has been killed by a terrorist from any of the seven majority-Muslim countries named in the ban.
Demonstrators had gathered at the U.S. embassy in Grosvenor Square at 11am, before making their way towards Whitehall.
He finished by saying "We can fight Trump's policies, we can fight that division".
It was the third big gathering in London to protest Donald Trump's policies since he took the office on Jan.20, as the 45th USA president.
The 90-day ban came into immediate effect by the U.S. and stopped the entry of residents from seven predominantly Muslim countries - Iraq, Syria, Iran, Sudan, Libya, Somalia and Yemen - to stop "radical Islamic terrorists" from entering to America.
Senate Panel Approves Trump EPA Nominee Scott Pruitt
The nominations will now head to the full Senate for final confirmation votes as early as next week. Democrats have opposed Priutt since President Donald Trump nominated him in December.
Approximately 10,000 people marched from the embassy to 10 Downing Street where the United Kingdom government offices are to also protest Prime Minister Theresa May who has so far failed to condemn the latest restrictions by the US administration.
Approximately 11,000 people are expected to attend the demonstration with pictures from the area showing streets filled with placard-wavers and banner-holders. "We want to ensure we aren't admitting into our country the very threats that our men and women are fighting overseas".
With Republican control of Congress and the White House, the new administration clearly has the power, if not a mandate, to make drastic changes in the way this country works, but Mr. Trump is also galvanizing opposition that could express itself strongly at the polls in 2018 and 2020. A petition calling for MPs to block the state visit has amassed more than a million signatures.
Despite the uproar, Downing Street confirmed the planned state visit would still go ahead on a date yet to be finalised.