The National Rifle Association (NRA) has named retired US marine colonel Oliver North, a conservative commentator best known for his central role in the 1980s Iran-Contra affair, as its new president.

Key points: Mr North was involved in the secret sales of arms to Iran by Reagan's administration

Mr North was involved in the secret sales of arms to Iran by Reagan's administration He was convicted of three felonies in 1989, but his convictions were overturned on appeal

He was convicted of three felonies in 1989, but his convictions were overturned on appeal He has also been a conservative radio talk show host and conservative commentator

The group named Mr North after its weekend annual meeting in Dallas, where United States President Donald Trump vowed not to tighten US firearm laws despite suggesting earlier this year he would take on the NRA in the wake of a mass shooting at a Florida school.

"Oliver North is a legendary warrior for American freedom, a gifted communicator and skilled leader," NRA chief executive Wayne LaPierre said in a statement.

"In these times, I can think of no one better suited to serve as our president."

Mr North, 74, who already serves on the NRA's board of directors, was a pivotal figure in the Iran-Contra affair involving secret sales of arms to Iran by Republican president Ronald Reagan's administration and the unlawful diversion of the proceeds to Nicaraguan rebels.

Mr North, who was a White House National Security Council aide, set up a weapons pipeline to the rebels even though Congress had forbidden military aid to them.

He was convicted of three felonies in 1989, but his convictions were overturned on appeal in 1990 as it was believed witnesses in the trial may have been influenced by a testimony Mr North had previously given under a grant of immunity from prosecution.

'The NRA doesn't need a new leader': Feinblatt

Wayne LaPierre has called Oliver North "a legendary warrior for American freedom". ( AP: Jacquelyn Martin )

Conservatives and gun-rights supporters have hailed him as a patriot who will vigorously battle efforts to restrict access to firearm.

But his appointment has been ripped by gun-control advocates who called his appointment symptomatic of an NRA tone-deaf given his role in the arms-trafficking scandal that engulfed the White House in the Reagan administration.

"The election of Oliver North is the clearest sign yet that the NRA is floundering in the face of plummeting popularity, scrutiny into its Russia ties, and [politicians] who are defying the gun lobby left and right," said John Feinblatt, president of Everytown for Gun Safety, founded by former New York mayor and billionaire Michael Bloomberg.

"The NRA doesn't need a new leader — it needs an entirely new direction."

Mr North will be the biggest celebrity to lead the 5-million-member gun lobby since Hollywood leading man Charlton Heston, who famously declared in 2000 that his guns would have to be taken "from my cold, dead hands".

Mr North has been a conservative radio talk show host and frequent commentator on conservative television networks since.

He is stepping down from his commentary role at Fox News television, the NRA said in its statement.

Mr North was picked by the NRA's board of directors, which elects a president every two years, and is expected to assume office within the next several weeks.

The NRA said its current president, Pete Brownell, planned not to seek a second term. Mr Brownell serves as CEO of Brownells Inc, a maker of firearm parts, accessories and ammunition.

Florida shooting marks turning point in gun debate

A bump fire stock attaches to an semi-automatic assault rifle to increase the firing rate. ( Reuters: George Frey )

The February massacre of 17 teens and educators at Marjory Stoneman Douglas High School in Parkland, Florida, had seemed to mark a turning point in America's long-running gun debate, sparking a youth-led movement for tighter gun controls.

Mr Trump said in the days following the massacre that politicians had to disagree with the NRA "every once in a while".

But since then, no major new federal gun controls have been imposed, although the Trump administration is pursuing a proposed regulatory ban on "bump stocks", which enable a semi-automatic rifle to fire a steady stream of bullets.

The devices were used in an October 2017 mass shooting in Las Vegas that killed 58 people.

Mr North, long a hero to some on the political right, lost as a Republican candidate for the US Senate from Virginia in 1994 after former first lady Nancy Reagan publicly said Mr North had a "great deal of trouble separating fact from fantasy" and "lied to my husband and lied about my husband".

Reuters/AP