A protester gets ready to take part in the Flood Wall Street demonstrations and march in lower Manhattan on Monday, preceding the United Nations' Climate Summit in New York.

Reuters/New York

Hundreds of protesters assembled in New York City's financial district on Monday, with some planning to risk arrest during an unsanctioned blockade on Wall Street to call attention to what organisers say is capitalism's contribution to climate change.

The Flood Wall Street demonstration comes on the heels of Sunday's international day of action that brought some 310,000 people to the streets of New York City in the largest single protest ever held on over climate change.

Kai Sanburn, a 60-year-old nurse and mother of two from Los Angeles, was among a crowd of nearly 1,000 people who had gathered at a waterfront park ahead of the planned sit-in. She said she had travelled to New York for Sunday's march but wanted to do more.

"Marching is wonderful but to really change things we really need to change things," Sanburn said. "The action here against Wall Street is really expressive of the feeling that Corps and capitalism no longer serve people they serve profit."

Organisers said later on Monday the group plans to march to the steps of the New York Stock Exchange for a sit-in and blockade, where some 200 people have said they will risk arrest by the New York City Police Department during the civil disobedience action, according to Leah Hunt-Hendrix, a spokeswoman for the protesters.

The group has roots in the Occupy Wall Street movement that started in a downtown Manhattan park in 2011 to protest what it called unfair banking practices that serve the wealthiest 1%, leaving behind 99% of the world's population.

Flood Wall Street organisers said they hope Monday's action will draw a link between economic policies and the environment, accusing top financial institutions of "exploiting frontline communities, workers and natural resources" for financial gain.

The event is part of Climate Week, which seeks to draw attention to carbon emissions and their link to global warming, and comes ahead of a September 23 UN Climate Summit.

Still, some protesters said they had come out in support but hoped to avoid arrest.

"I'm not planning on participating in the sit-in. I do environmental work outside of the Occupy movement so I'm not able to risk that," said Dana Ruygrok, a 19-year-old environmental activist from Chicago.

"Yesterday was awe-inspiring so I thought I want to come here and find out what it's all about."