PARIS — More than 50 world leaders are gathering in Paris for a summit that President Emmanuel Macron hopes will give new momentum to the fight against global warming, despite U.S. President Donald Trump’s rejection of the Paris climate accord.

Some 3,100 security personnel are fanned out around Paris for Tuesday’s event, including extra patrol boats along the Seine River. Macron will accompany the visiting leaders to the summit site on a river island by boat.

Sean Penn, Arnold Schwarzenegger and Elon Musk are among prominent figures joining the world leaders at the summit, which marks the second anniversary of the Paris accord.

Participants are expected to announce billions of dollars’ worth of projects to help poor countries and industries reduce emissions.

Macron, who’s also using the event to raise his international profile, did not invite Trump.