Rips Pres. Biden, Reflects On 9/11

Former president Donald Trump has taken the mic at the Evander Holyfield vs. Vitor Belfort fight ... and it didn't take long for him to go off on President Joe Biden and the crisis in Afghanistan.

As we previously reported, The Donald is providing alternate broadcast commentary for the Triller Fight Club event Saturday night ... and opened up his first appearance by discussing the 20th anniversary of the terrorist attacks on September 11, 2001.

While Trump didn’t mention Biden by name, he alluded to "very bad decisions" made during the end of the Afghanistan conflict. He promised America would "comeback like nobody’s ever seen."

"As a country, the United States, this is certainly one of the…