While addressing more than 50 world leaders at a nuclear summit he said the gathering was an opportunity to make sure that all nations did everything in their power to block terrorist groups from developing nuclear weapons.

The president noted "significant progress" made regarding nuclear security and pledged that the U.S. would continue to cooperate to reduce nuclear stockpiles and keep them safe – an assertion that contrasts with reports earlier this year that Obama has approved an upgrade to the U.S. nuclear arsenal to the tune of an estimated $1 trillion over the next 30 years.

"More than a dozen nations have removed all their highly enriched uranium and plutonium," Obama said of the radioactive elements essential to building nuclear bombs.

He added that nations have also improved their own nuclear security, including stronger regulations and more physical security at nuclear facilities.

"And the good news is we’ve made significant progress," he said. "Because of our coordinated efforts, no terrorist group has succeeded thus far in obtaining a nuclear weapon or a dirty bomb made of radioactive materials."

But terror groups have long sought nuclear material and they should be prevented from obtaining it, he said.

"Individuals involved in the attacks in Paris and Brussels videotaped a senior manager who works at a Belgian nuclear facility," according to Obama.

"ISIL has already used chemical weapons, including mustard gas, in Syria and Iraq."

Dutch Prime Minister Mark Rutte followed Obama and said growing international cooperation and commitment since the last summit in 2014 has helped to reduce the amount of nuclear material in circulation that continues to decline.

Anadolu Agency