Mayor Bill de Blasio took the fight for climate protection to President Donald Trump's doorstep, holding a rally at Trump Tower Monday to promote his "Green New Deal."

People gathered to support the mayor's $14 billion plan, which aims to reduce greenhouse gas emissions in the city by 30 percent in the next 10 years.

Opponents were also in attendance, riding the escalator with anti-de Blasio and pro-Trump signs. 

One of the most controversial aspects of the plan puts strict new energy guidelines on skyscrapers.

"Clearly, the Trump organization is a little sensitive to the fact that we are calling them out for what they are doing to the climate, and the way this building is a part of the problem, but we will not back down," the mayor said. "We don't back down in New York City, do we?"

Fe Blasio also says he will announce whether or not he'll make a 2020 run for the White House by the end of the week.