EU lawmakers gave approval Wednesday for the European Investment Bank (EIB) to do business in Iran, overcoming an attempt to block the move and keeping alive plans to save the 2015 nuclear deal with Tehran that Washington has abandoned.

The EIB, the European Union's not-for-profit long-term investment arm, is a key pillar of the bloc's attempts to maintain business links with Iran in the face of Washington's decision to re-impose sanctions on the Islamic Republic.

However, the EU lawmakers' decision does not oblige the EIB to work with Iran — a move that could jeopardize its ability to raise money on U.S. markets and so have far reaching consequences for its operations.