UPDATE 1-Core sanctions should stay until Iran addresses all concerns -U.S.

Thu Oct 3, 2013 8:27pm IST

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WASHINGTON Oct 3 (Reuters) - A top U.S. official on Thursday held out the prospect of limited sanctions relief for Iran if it takes confidence-building steps to allay concerns about its atomic program, but said the fundamental sanctions must stay until all concerns have been dealt with.

Under Secretary of State for Political Affairs Wendy Sherman also told lawmakers it would be helpful for the U.S. Senate to hold off on imposing additional sanctions on Iran ahead of an Oct. 15-16 meeting with Iranian officials in Geneva.

While saying the Obama administration was committed to fully enforcing the U.S. sanctions that are already on the books, Sherman said the administration's ability to do so was hampered by the U.S. government shutdown. (Reporting by Arshad Mohammed; Editing by Vicki Allen)