UNITED NATIONS — Natural disasters have nearly quadrupled in number since 1970 and the United States has experienced the most disasters since 1995, followed by China and India, the United Nations chief said Tuesday.

Secretary-General Antonio Guterres told reporters that in recent days the world has seen the "dramatic aggravation" of climate change with "unprecedented events" caused by storms and flooding from Texas to Bangladesh, India, Nepal and Sierra Leone.

Before the current floods, he said, preliminary reports registered 2,087 deaths this year from natural disasters. With the latest floods, that number will at least double.

In the last two months, more than 1,000 people have been killed in flooding events across India, southern Nepal and northern Bangladesh and some 40 million have seen their homes, businesses or crops destroyed. Last month, more than 1,000 people died from a mudslide and flood that hit Sierra Leone's capital Freetown. And last week, Hurricane Harvey dumped almost a year's worth of rainfall on Houston, America's fourth-largest city. It destroyed some 7,000 homes and damaged more than 37,000 others in Texas and is blamed for at least 60 deaths.

Guterres said last year 24.2 million people were displaced by sudden disasters — "three times as many as by conflict and violence."

He noted that scientists caution about linking any single weather event with climate change. "But they are equally clear that such extreme weather is precisely what their models predict will be the new normal of a warming world," Guterres said.

The secretary-general was asked whether he would try to persuade President Donald Trump to keep the United States in the Paris climate agreement when they meet during the U.N. General Assembly's annual ministerial meeting that starts Sept. 19.

"We are totally committed to the Paris agreement," Guterres said. "We hope that all countries will understand that it's not only the right thing to do it's also the smart thing to do because the green economy is the economy of the future."