Hollywood actor Danny Glover compared the devastation inflicted on Haiti by the January 12 earthquake to the destruction of the Second World War, but said the world was "paying attention" and ready to help.

Lethal Weapon star Glover, a former United Nations goodwill ambassador, made the comments over the weekend during a visit to the earthquake-hit Caribbean nation, in which he saw camps housing some of the hundreds of thousands of homeless survivors.

"We have to understand the magnitude of this, really the magnitude of this," Glover said before meeting with another Hollywood star, Sean Penn, who has a relief charity operating in wrecked Port-au-Prince.

Glover said the disaster in Haiti should provide an opportunity for the western hemisphere's states to help their poorest member.

"I think the world is still paying attention," he said, looking ahead to a donors' pledging meeting for Haiti in New York on March 31.