An Iranian government official on Wednesday threatened to ramp up the country’s nuclear enrichment above levels agreed upon in the 2015 nuclear accord brokered with the Obama administration and other world powers.

“Iran is ready to increase the speed of its nuclear activities in various areas, especially enrichment, several times more than pre-JCPOA era,” said Behrouz Kamalvandi, a spokesman for the Atomic Energy Organization of Iran, using the nuclear deal’s formal name.

Kamalvandi’s comments came in response to President Donald Trump’s threat to impose harsh financial sanctions on the Islamic Republic. Trump is slated to announce his decision on the sanctions Friday.

“If the sanctions suspension are not extended, that would violate the nuclear deal and the Islamic Republic of Iran will take first retaliatory action immediately,” Kamalvandi said.

In October 2017, Trump announced his refusal to recertify Iran’s compliance with the nuclear deal as part of a new and tougher approach towards the Islamic Republic.

“We cannot and will not make this certification,” Trump said at the time. “We will not continue down a path whose predictable conclusion is more violence, more terror and the very real threat of Iran’s nuclear breakout.”

While Trump’s move stopped short of pulling the U.S. out of the agreement, he handed Congress the decision on whether to reimpose sanctions originally lifted in 2015. The U.S. administration must certify every 90 days whether it believes Iran is in compliance with the nuclear deal.