U.N. Secretary General António Guterres issued a veiled warning to President Donald Trump during his first major speech on global warming should the U.S. withdraw from the Paris agreement on climate change.

Guterres said countries can either “get on board or get left behind” when it comes to taking action on global warming because they will miss out on new economic opportunities from greener industries.

“Climate change is undeniable,” Guterres said in his speech at New York University Tuesday. “Climate action is unstoppable. And climate solutions provide opportunities that are unmatchable.”

Trump said he would decide this week whether or not he will withdraw from the Paris climate agreement, which the Obama administration joined in 2016 along with 146 other countries.

European leaders lobbied Trump to stick with the agreement during the G7 summit in late May, but Axios reported Saturday that Trump had privately told confidantes he would withdraw from the accord.

Guterres seems to be making a last-minute appeal to the Trump administration to stick with the Paris agreement, specifically pointing to the alleged economic benefits of pushing policies to phase out fossil fuels.

“The sustainability train has left the station,” Guterres said. “Get on board or get left behind.”

White House economic adviser Gary Cohn told reporters last week that Trump would prioritize economic growth over global warming if the two came into conflict. Germany has focused on the economic benefits of fighting global warming to entice the Trump administration.

“Some may seek to portray the response to climate change as a fundamental threat to the economy,” Guterres said. “Yet what we are witnessing in these early years of a systemic response is the opposite.”

“The real danger is not the threat to one’s economy that comes from acting,” he continued. “It is, instead, the risk to one’s economy by failing to act.”

But complying with the Paris agreement means phasing out fossil fuels — industries Trump promised to boost during his presidential campaign.

Republicans argue there could be legal risks to Trump’s agenda should he stay in the Paris agreement.

“Withdrawing from the Paris Agreement is an important and necessary step toward reversing the harmful energy policies and unlawful overreach of the Obama era,” 10 Republicans states attorneys general wrote in a letter sent to Trump in May.

Follow Michael on Facebook and Twitter

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact licensing@dailycallernewsfoundation.org.