NEW YORK, Jan. 13 (Xinhua) -- With New York City filing a lawsuit against some oil companies for allegedly contributing to global warming, some experts are expecting it to build momentum inside the U.S., while the affected firms are calling it a ploy to politicize climate change.

New York City Wednesday announced it had filed a lawsuit against the five largest oil companies for contributing to global warming.

"The City will be seeking damages from BP, Chevron, ConocoPhillips, Exxon Mobil, and Royal Dutch Shell for the billions of dollars the City will spend to protect New Yorkers from the effects of climate change," a statement from the mayor's office said Wednesday.

Meanwhile, New York City Mayor Bill de Blasio and Comptroller Scott Stringer also announced that they would divest the city's five pension funds of roughly 5 billion U.S. dollars in fossil fuel investments. The funds together are worth 189 billion dollars.

"Pension funds of other major US cities will follow," Jeffrey Sachs, an economist at New York's Columbia University, told The Guardian.

Since the lawsuit could take years to resolve, John Hopkins University's economist Paul Ferraro said the act could be seen as "a tool of collective action that can politically isolate companies."

The oil companies, on the other hand, called the suit a political "conspiracy".

Exxon said Monday that "a collection of special interests and opportunistic politicians are abusing law enforcement authority and legal process to impose their viewpoint on climate change."

A spokesperson for Chevron said the lawsuit will "do nothing to address the serious issue of climate change," The New York Times reported.

Linda Kelly, senior vice president of the National Association of Manufacturers, called the suit "part of a deep-rooted, politically motivated campaign to undermine manufacturing in America," Bloomberg reported.