Trump described Mexicans as "phenomenal people" in his first press conference since being elected US president.
The remarks contrast with controversial remarks he made on the campaign trail, when he described Mexicans as "drug dealers, rapists and criminals."
During the conference, he repeated his campaign trail pledge that Mexico would be made to pay for a wall on the Mexico-US border.
Before the conference Trump furiously denied allegations that Russia had compromising information on him, saying Moscow "never tried to use leverage on me".
Mr Trump condemned US intelligence agencies for allowing "fake news" to "leak" into the public, asking: "Are we living in Nazi Germany?"
An unsubstantiated report, allegedly presented to Trump last week, contained claims that the Kremlin has a dossier of compromising information the president elect, stating that key members of his team secretly met Russian officials.