Protesters who massed a year ago to speak out against what they say is a system of corporate greed and economic inequality in the United States are set to mark the anniversary of their movement with demonstrations in New York's financial district.

Occupy Wall Street is calling on supporters to assemble Monday outside the New York Stock Exchange and to disrupt traffic in the area. Organizers say the demonstrations are in favor of a “just and sustainable world.”

Activists began their New York protests on September 17 last year, and assembled a camp in a nearby park to organize and discuss their efforts. The scene was repeated in cities across the country, including Washington and Oakland.

Protesters pushed for a wide array of reforms, including on banking, campaign finance and environmental issues.

But after several months, police broke up the camps in New York and elsewhere, and the movement that sparked conversation about wealth distribution and corporate earnings lost momentum amid unfocused demands.

Monday's planned demonstrations come weeks before Americans vote in a presidential election in which President Barack Obama and Republican challenger Mitt Romney have largely focused on economic issues.