Los Angeles: US President Donald Trump has sent an Australia Day message, declaring America has no better friend than Australia.

The message was delivered by acting Secretary of State Thomas Shannon jnr and comes just days after Trump killed US participation in the Trans-Pacific Partnership with Australia and other allies and as he considers whether to make it harder for Australians and Kiwis to travel to the US.

"On behalf of President Trump and the American people, it is my honour to congratulate the people of Australia as you celebrate this Australia Day, 229 years after the arrival of the First Fleet at Sydney Harbour," Shannon said.

"It has been over 75 years since your Commonwealth and the United States established diplomatic relations, but connections between America and Australia reach back to that fleet."