White House hopeful Donald Trump says he is unlikely to have a good relationship with British Prime Minister David Cameron and has suggested London’s new Muslim mayor, Sadiq Khan, is “ignorant” and should take an IQ test.

The row between the newly-elected Mayor of London, Sadiq Khan and U.S. Republican presidential hopeful Donald Trump doesn't seem to be calming anytime soon.

Newly-elected London Mayor Sadiq Khan has snubbed Republican nominee Donald Trump’s suggestion he will allowed entry to the US as an exception under any future country-wide ban on Muslims, labelling Trump’s views “ignorant.”

“I’ll be stopped f-rom going there by virtue of my faith,” Sadiq Khan said.

Sadiq Khan became London's first Muslim mayor Saturday, as voters rejected attempts to taint him with links to extremism and handed a decisive victory to the bus driver's son f-rom south London.

Labour politician Sadiq Khan is leading the London mayoral elections. If he wins, he will become the first Muslim mayor of a major European capital.