Biden says he has been to the aftermath of more shootings than any other U.S president.
It follows a deadly shooting at a mosque in Christchurch in 2019, where a gunman killed 51 worshippers.
Biden drew on Ardern’s “galvanising action on climate change; the global effort to curb violence, extremism, and online, like happened in Christchurch”.
The New Zealand leader banned most-semi-automatic weapons in the wake of the Christchurch attack.
“If there’s anything that we can share that would be of any value, we are here to share it,” Ardern says.
The two leaders agreed to cooperate on violent extremism, gun violence and climate change.