Liberal former New York City Mayor Michael Bloomberg is pushing a $200 million program to help mayors push back against the Trump administration and Congress on areas such as climate change, gun control, and immigration.

Mayor Ed Lee of San Francisco and Mayor Eric Garcetti of Los Angeles are the highest-paid and second-highest-paid mayors in America, respectively, according to a new report by the American City Business Journal.

Mayors from five California cities on Friday signed a letter urging Congress not to reject vetted refugees, including those from Syria, that seek to come to the United States.

The United States will be heavily represented at the workshop, with its eleven politicians making up nearly 20 percent of the total participants. There will be no one participating from some of the countries with the worst record of polluting the environment, including Russia, China and the former Soviet Republics.

The workshop, titled “Modern Slavery and Climate Change: The Commitment of the Cities,” will explore the connection between climate change and new forms of slavery. The official website of the workshop asserts that it is a “fact” that “global warming is one of the causes of poverty and forced migration, which are breeding grounds for human trafficking, forced labour, prostitution and organ trafficking.” Mayor de Blasio will deliver a speech describing his administration’s environmental plan for New York City.