The four-time Olympic gold medallist, who has lived in Oregon for the last six years, is originally from Somalia.
Under Trump’s latest controversial executive order, which bans refugees entering the US from Syria and six other Muslim-majority countries, Farah faces the possibility of not being allowed home to see his family.
It is believed the athlete is currently training in Ethiopia.
People from Somalia, Iraq, Iran, Libya, Sudan, Yemen and Syria have been temporarily barred from entering the US, as have all refugees.
Farah said on Sunday that the US President’s policy “comes from a place of ignorance and prejudice”.
He added: “Now, me and many others like me are being told that we may not be welcome.”
Farah’s statement in full:
“On 1st January this year, Her Majesty The Queen made me a Knight of the Realm. On 27th January, President Donald Trump seems to have made me an alien.
“I am a British citizen who has lived in America for the past six years - working hard, contributing to society, paying my taxes and bringing up our four children in the place they now call home. Now, me and many others like me are being told that we may not be welcome. It’s deeply troubling that I will have to tell my children that Daddy might not be able to come home - to explain why the President has introduced a policy that comes from a place of ignorance and prejudice.
“I was welcomed into Britain from Somalia at eight years old and given the chance to succeed and realise my dreams. I have been proud to represent my country, win medals for the British people and receive the greatest honour of a knighthood. My story is an example of what can happen when you follow polices of compassion and understanding, not hate and isolation.”
Tory MP Nadhim Zahawi, who was born in Iraq, warned on Sunday that Trump was playing into the hands of so-called Islamic State militants by banning millions of Muslims entering the US.
He accused the President’s new immigration rules of being “counterproductive” to his long-stated desire to defeat Islamic extremism, adding: “For the first time in my life last night I felt discriminated against. It’s demeaning. It’s sad.”