Witnesses to the incident in May previous year said Gianforte became enraged over coverage he perceived as biased before throwing Jacobs to the ground and punching him. Gianforte pleaded guilty to misdemeanor assault and was fined and sentenced to community service and anger management classes.
The violent incident happened on the 24 May previous year when the Guardian's political correspondent, Ben Jacobs, asked Gianforte a question about healthcare policy in the course of a special congressional election in Montana. And then I said "Well, wait a minute. He's going to lose the election,"' Trump told the crowd. His comments Thursday also came as the slaying of Washington Post contributing columnist Jamal Khashoggi at the Saudi Consulate in Istanbul continued to brew as an worldwide crisis. "Hey, to go out and say, as a guy who is a little bit - who is un-PC, and probably won because he's un-PC".
Trump has also denied covering for Saudi Arabia over the suspected murder.
While in a statement, the Guardian's US editor John Mulholland said: "To celebrate an attack on a journalist who was simply doing his job is an attack on the first amendment [of the US Constitution] by someone who has taken an oath to defend it".
In late October 2018, as the ugly story of journalist and United States resident Jamal Khashoggi's disappearance and suspected brutal murder at the behest of Saudi Arabia's crown prince continued to unfold, the Trump administration and its allies appeared to brush off any sense of urgency about ongoing investigations.
He added: "We hope decent people will denounce these comments and that the president will see fit to apologise for them".
President Donald Trump, however, praised Gianforte's actions during a rally in Missoula on Thursday. He wished that the president had surprised him, he said.
This latest praise from Mr Trump is unlikely to improve his relationship with the media, which he has previously labelled the "enemy of the people".
Earlier today, the Guardian also condemned Trump's praise of Gianforte, whose reporter Ben Jacobs was on the receiving end of the congressman's assault.