Updated

The Obama administration is expanding U.S. sanctions on Iran over its suspect nuclear program, hitting additional companies and individuals with penalties.

The administration said Wednesday the targeted individuals and institutions are helping Iran to develop its nuclear and missile programs and to evade international sanctions.

The new sanctions are a first step in implementing an Iran sanctions resolution passed by the U.N. Security Council last week.

The White House said Wednesday the additions to its sanctions list include Iran's Post Bank for its support of nuclear proliferation. That brings to 16 the number of Iranian-owned banks on the U.S. list.