Trump introduced a 90 day suspension on arrivals from seven Muslim majority Middle Eastern and African countries over the weekend, though the Foreign Office has claimed that British passport holders will be unaffected.
However, Khan has been vocal in his criticism of the policy, and will tonight tell an audience, expected to include the US' most senior diplomats, that the ban is “cruel, prejudiced and counterproductive”.
Although Trump has yet to appoint an ambassador to the UK, the event is expected to welcome the US charge d'affaires – the diplomat who heads up an embassy in the absence of an appointment.
Sadiq will also reiterate his call for the government to rescind its offer of a full state visit for President Trump while the ban remains in place.
Khan is expected to say: “You don’t need me to tell you that there’s no contradiction between subscribing to Western values – of human rights, democracy, the rule of law and freedom of speech – and being a Muslim.
“Nor do you need me to tell you that targeting people for no reason other than their faith or their country of birth is cruel, prejudiced and counterproductive."
He will add that Trump's efforts play into the hands of extremists seeking to divide the world.
“As an international community, I believe we have a responsibility to show moral leadership and so my ask of you tonight is this: join me in speaking out against this ban and condemning it for what it really is – discriminatory, self-defeating and completely un-American," Khan will say.
However, London Assembly Conservatives also noted that Khan will host diplomatic staff from 11 countries that currently bar Israeli passport holders from entry.
London Tory Andrew Boff said: “I fully support the Mayor’s condemnation of President Trump’s divisive travel ban but he should also be willing to condemn those countries that discriminate against citizens from Israel – particularly when he is hosting their representatives at a drinks reception at City Hall.
He added: “I sincerely hope the Mayor will use tonight’s reception to highlight the discrimination faced by Israeli citizens in the eleven countries represented at the event.”