World leaders are in Paris this week to try to come up with a global action to address climate change, but Republican presidential aspirant Carly Fiorina is unimpressed.

In an interview with Fox News, the former Hewlett-Packard chief executive described U.S. President Barack Obama as "delusional" for his earlier statements branding climate change as the biggest security threat to the country.

"Well, that's delusional. It is delusional for President Obama and Hillary Clinton and anyone else to say that climate change is our near-term most severe security threat," Fiorina said, as quoted by Breitbart.com.

A day before the Paris climate talks which began on Monday, the Republican presidential hopeful also said that it is very unlikely that countries around the world will be able to come up with a sufficient solution to climate change.

"If you read the fine print of the science, what the scientists tell us, all those scientists who tell us climate change is real and man-made, they say a single nation acting alone will make no difference at all. It would take a concerted global effort. I think the likelihood is near zero," Fiorina said.

In the same interview, Fiorina said the biggest security threats facing the U.S, are the Islamic State (ISIS) terrorist group, Iran and Russia—not climate change.

"President Obama continues to think that somehow our behavior causes terrorism, so he says the Climate Change Summit is a powerful rebuke. No, it's not. The terrorists don't care that we're gathering in Paris other than it provides a target," Fiorina said.

"Just as he said Republicans are giving terrorist a recruiting tool because we don't think refugees should be allowed in the country if we don't properly vet them.

President Obama is delusional about the threat, which is apparently he won't do anything about it," she added.

The Republican presidential hopeful, who ranked sixth in the latest popularity surveys, further indicated that Obama is just wasting his time attending the climate talks in the French capital.

"I think it would be far more productive if President Obama indeed was there leading an international coalition to stop human trafficking or for humanitarian relief for the refugees or international coalition to defeat ISIS. All those would be more useful than time in Paris tackling about climate change," she said.

In his 2015 State of the Union address, Obama called climate change "an urgent and growing threat," saying that nothing poses a greater threat to further generations than the issue of a changing climate.