Jason Momoa didn't mince words in his speech at the United Nations on Friday.

The Aquaman leading man spoke out during a session about SAMOA Pathway, the 2014 U.N. program aimed at Small Island Developing States.

The Honolulu, Hawaii native, 40, noted that island nations are on 'the front lines in this environmental crisis' and often bear the brunt of heavy ocean pollution and impact of industry.

Using his voice: Aquaman star Jason Momoa, 40, spoke out on climate change at the U.N. on Friday in a session about SAMOA Pathway, a program aimed at Small Island Developing States

'Island nations contribute the least to this disaster, but are made to suffer the weight of its consequences,' said the actor. 'Our governments and corporate entities have known for decades that immediate change is needed. Yet change still has not come.'

He added that 'entire islands are drowning into the sea due to the enormous volume of emissions generated by first world countries.'

The 6ft4 screen star took to Instagram with a clip of his speech for his 13.4 million followers about the high-profile outing.

'For those who couldn’t watch it live, watch me fumble through my very honest and direct speech,' he wrote. 'No BS. Nothing sugar coated, just straight from the heart. We’ve been half a**ing our global efforts to reverse the climate crisis and this can’t continue.'

urgency: Momoa stressed to 13.4 million followers that current standards regarding pollution and industry 'can't continue' for the good of the environment

Family first: The A-list action hero thanked his friends and relatives for having his back

Stating his case: Jason told UN leaders that 'island nations contribute the least to this disaster, but are made to suffer the weight of its consequences'

The actor, who first played Aquaman in 2016's Batman v Superman: Dawn of Justice and again in 2017's Justice League, said conditions need to change immediately 'for the future of our planet,' adding that 'the wave of change is coming' for Small Island Developing States.

In a separate post, he called the speech 'a life changing moment,' adding that it was 'a true honor to represent island nations at the UN.'

The actor thanked his family for their support, saying, 'It takes an amazing team and support system to pull off something like this. I am deeply grateful to my wife and children, my mother' and others.

Momoa has past been vocal about environmental concerns, as in August, he was on hand in Hawaii to protest construction on a volcano as part of the Thirty Meter Telescope project.