The United States has aggressively ramped up its financial sanctions on Iran this year, but a measure that takes effect in February could have the most dramatic impact yet, the Treasury Department’s top sanctions official said on Thursday, December 6, Reuters reported. Starting Feb. 6, U.S. law will prevent Iran from repatriating earnings it gets from its shrinking oil export trade, a powerful sanction that will “lock up” a substantial amount of Tehran’s funds, said David Cohen, Treasury undersecretary for terrorism and financial intelligence. The Senate agreed to a package of sanctions last week that would add similar restrictions on payments for Iran’s natural gas exports, and bans the sale or transfer of precious metals to Iran. It is part of a defense bill that may be finalized by the Senate and House of Representatives by the end of the year.