"Joe Biden has had the most disastrous first month of any president in modern history," Trump said on Sunday in his first major public appearance since leaving office.

Trump particularly pointed to the emerging border crisis in the US, criticizing Biden’s immigration policy and calling it a betrayal of America's core values.

"Already the Biden administration has proven that they are anti-jobs, anti-family, anti-borders, anti-energy, anti-women and anti-science," Trump said, adding "In just one short month we have gone from ‘America First’ to ‘America Last.’"