U.S Secretary of State Mike Pompeo announced on Wednesday that the U.S. will end all sanction waivers that allowed Chinese, European, and Russian companies to work with Iranian nuclear sites without coming under U.S. sanctions.

“Today, I am ending the sanctions waiver for JCPOA (also known as the Joint Comprehensive Plan of Action) related projects in Iran, effective in 60 days,” Pompeo said in a Tweet Wednesday. “Iran’s continued nuclear escalation makes clear this cooperation must end. Further attempts at nuclear extortion will only bring greater pressure on the regime.”

The UN Security Council claims that the JCPOA was necessary to ensure nuclear nonproliferation in Iran and to stabilize the region as a whole. The waivers allowed other countries and companies to work with Iran to modify the existing nuclear facilities and ensure compliance with nuclear nonproliferation strategies.

But the administration believed Iran was ramping up its nuclear proliferation efforts.

“The regime’s nuclear extortion will lead to increased pressure on Iran and further isolate the regime from the international community,” Pompeo said in a statement Wednesday.