Speaking today at the United States Conference of Mayors in Miami, New York City’s former mayor, Michael Bloomberg, released plans for a $200 million program that will help fund innovative policy changes at the city level, as first reported by The New York Times.

The program, called the American Cities Initiative, is funded through Bloomberg Philanthropies and will take place over the next three years. It’s a municipally-focused extension of Bloomberg’s existing advocacy for national policies, including climate change, gun violence, public health, and immigration.

“You can argue that if people in cities use less energy, the coal-fired power plants outside the cities would pollute the air less,” he told the Times. “You can make the case that immigration is a city issue, because that’s where a lot of people live and work.”

One of the major components of the initiative is a “Mayors Challenge,” a national competition where city mayors are invited to submit proposals for policy experimentation that addresses their respective city’s most urgent problems. The grand prize? $5 million. Four more cities will receive up to $1 million and 35 ‘Champion Cities’ will win up to $100,000 to test their ideas and build local support, according to the challenge’s website. Bloomberg has launched similar competitions before, but in Europe and Latin America.

The former mayor has constantly been an aggressive advocate against President Donald Trump’s policies, especially regarding issues around climate change and immigration. In June, Bloomberg vowed to fight climate change in spite of Trump’s decision to pull out of the Paris Climate Accord by pledging $15 million to the United Nations and gathering support at the city level.

At the conference, Bloomberg said that the program is meant to “advance important policies and legislation particularly with respect to education, climate change, and public health,” according to Miami Patch. The support will vary by city; in some cases, it could be policy support to help improve energy efficiency, while others could be in the form of advocacy.

This program comes at a crucial time when the Trump administration has proposed major funding cuts to government agencies, including the Department of Housing and Urban Development (HUD), which cities usually rely on for money. In his interview with the Times, Bloomberg emphasized the increasing need for cities to “replace Washington, and in some cases, state governments, to provide services.”