Kyle Rittenhouse u-turns after saying he won't vote Trump

Conservative campaigner Kyle Rittenhouse has promised to support Donald Trump in November's US election, reversing comments hours earlier that he would vote against him because he was "bad" at protecting gun rights.

Mr Rittenhouse, now 21, shot dead two men during racial unrest in Kenosha, Wisconsin, in August 2020. He was cleared of all charges the following year after arguing self-defence.

Instead of Trump, he said he planned to write in former Libertarian presidential nominee Ron Paul on the ballot.

Trump has repeatedly vowed to protect Americans' right to own guns and to roll back Biden-era restrictions on firearms.

Mr Rittenhouse - who became a cause célèbre among some US conservatives during his trial - met Trump just a week after being cleared of charges in November 2021, with the president calling him a "fan".

In an online post early on Friday, Mr Rittenhouse - now outreach director for the group Texas Gun Rights - said that "unfortunately, Donald Trump has bad advisers, making him bad on the Second Amendment", which protects gun ownership in the US.

"If you cannot be completely un-compromisable on the Second Amendment, I will not vote for you," he said on X, formerly Twitter. "We need champions for the Second Amendment or our rights would be eaten away and eroded each day."

"I support my decision and I have no take-backs," he added.

In a later post, however, he wrote that in the last 12 hours he had had "a series of productive conversations with members of the Trump's team and I am confident he will be the strong ally gun owners need to defend our Second Amendment rights".

He called his comments from the night earlier "ill-informed and unproductive".

Soon after his original post, Mr Rittenhouse shared another post from the leader of the National Association for Gun Rights outlining the group's criticism of Trump's record.

It cites his support while president for raising the minimum age for gun purchases and openness to expanded background checks. Trump quickly backed away from those ideas at the time.

The list also included Trump's 2018 ban on bump stocks, an accessory that allows semi-automatic rifles to fire hundreds of bullets per minute, similar to a machine gun. The Supreme Court overturned the prohibition two months ago.

Mr Rittenhouse's video drew the ire of some Trump supporters, some of whom responded with expletive-laden tirades.

"The left hates you and now Maga will shun you," one user wrote.

But the former president's political opponents celebrated what some termed a "break-up" between Mr Rittenhouse and Trump.

"When you've lost Kyle Rittenhouse... Trump campaign is in trouble," posted the Lincoln Project, an anti-Trump group.

Trump, now the Republican nominee for president, has repeatedly vowed to protect gun rights if elected in November's election.

In February, he told a meeting of the National Rifle Association that “every single Biden attack on gun owners and manufacturers will be terminated on my very first week back in office".

In 2021, the most recent year for available data, almost 49,000 people in the US died of firearms-related injuries, according to the Centers for Disease Control and Prevention.

The figure includes both murders and suicides.