, Mr Khan, 46, said also said the
Trump travel ban was a propaganda win for ISIS.
"The reality is that if you look at other global cities, Berlin, Istanbul most recently, but Paris and other parts of the world. Our global cities are targets for terrorist," he said.
His comments come just a day after a suspected jihadi terrorist was shot dead near the Louvre in Paris.
Mentioning his row with Westminster over money for Scotland Yard, he said: "If the government changes the police funding formula and if they fail to fund London as a capital city.
"I think keeping London safe is becoming increasingly difficult."
The mayor warned of an increased threat from homegrown terrorism — a shift from "upstream" attackers coming into the country.
"We saw in the last year-and-a-half, Londoners born and raised in our city radicalised in their bedrooms to the extent where they jump on a plane and go to Syria."
He added: "The best way it has been explained to me is that the bad guys are evolving."
Mayor Khan offered to "educate" the US President on how to tackle terror, saying Trump had a "blind spot" over relations with the Muslim community.
"I am all for people who have a blind spot or need illuminating or educating being educated," he said.
"So I am in favour of explaining to President Trump why it is important for us to build bridges not walls."
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