U.S. Treasury Secretary Steven Mnuchin, National Security Advisor John Bolton and Vice President Mike Pence listen as President Donald Trump announces his intention to withdraw from the JCPOA Iran nuclear agreement during a statement in the Diplomatic Room at the White House in Washington, U.S., May 8, 2018. REUTERS/Jonathan Ernst

WASHINGTON (Reuters) - There will be ‘wind down’ periods of 90 to 180 days, and perhaps other durations, for existing Iran contracts for companies to adjust to U.S. President Donald Trump’s decision to withdraw from the 2015 Iran nuclear deal and revive U.S. sanctions, White House national security adviser John Bolton said on Tuesday.

“Within the zone of economics covered by the sanctions, no new contracts are permitted. (The U.S.) Treasury will be announcing in the next few hours what they call ‘wind down’ provisions that will deal with existing contracts and there will be varying periods within these contracts to be wound down,” Bolton told reporters. “Some will extend to six months. Some might be 90 days. There might be other provisions as well.”