The White House pushed back firmly on Monday against the notion that President Donald Trump may have picked a fight with London mayor Sadiq Khan because he is a Muslim.

'Not at all,' Trump spokeswoman Sarah Sanders shot back at the suggestion from a CNN reporter.

'And I think that to suggest something like that is utterly ridiculous.'

Trump has had a rocky relationship with Muslim groups since calling in December 2015 for 'a total and complete shutdown of Muslims entering the United States' pending a review of homeland security safeguards.

The president came under fire this week for taking issue with Khan's stiff-upper-lip advice to Londoners following Saturday's deadly terror attack.

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President Donald Trump did not attack London Mayor Sadiq Khan (right) because of his Muslim faith, the White House insisted on Monday

White House deputy press secretary Sarah Huckabee Sanders told a CNN reporter that 'to suggest something like that is utterly ridiculous'

Khan is the first Muslim mayor of a major Western capital city.

He said Sunday that there was 'no reason to be alarmed' at the sight of a massive armed police presence in the city's center – a notion that sent the president into overdrive.

'At least 7 dead and 48 wounded in terror attack,' Trump tweeted, 'and Mayor of London says there is "no reason to be alarmed!"'

'We must stop being politically correct and get down to the business of security for our people. If we don't get smart it will only get worse,' he added.

The president doubled down Monday on his feud with Sadiq Khan, despite appearing to take him out of context on Sunday (above)

Three jihadis attackers (one suspect seen lying down, with fake bomb vest) drove into people on London Bridge just after 10 p.m. Saturday, then ran through a popular nightlife area, attacking civilians with knives before police shot them dead

On Monday morning he doubled down on the attack, tweeting: 'Pathetic excuse by London Mayor Sadiq Khan who had to think fast on his "no reason to be alarmed" statement. MSM [mainstream media] is working hard to sell it!'

It was not clear what 'excuse' the president was referring to.

The mayor hit back Monday night, accusing Trump of 'fuelling division' and insisting he did not have 'time' to respond in greater detail.

Sanders said Monday that Trump is committed to putting a renewed emphasis on national security, and denied that the president had taken Khan's words out of context – when an ABC News reporter claimed he 'directly misrepresented' him.

'I don't think that's actually true. I think that the media wants to spin it that way,' she deadpanned.

An increased armed police presence in a city where regular beat cops don't carry guns can be interpreted as a sign that authorities believe an attack is imminent.

Trump, Sanders hinted, interpreted Khan's calm as a message of complacency – referring not to the uniformed troops but to the terror threat they represented.

'I think that the point is, is there is a reason to be alarmed,' she said.

'We have constant attacks going on, not only there but across the globe. And we have to start putting national security and global security at an all-time high.'

'President Trump has been very clear that's his priority, and he's not backing away from that.'