U.S. Iran bill makes nuclear deal harder, but not impossible

WASHINGTON (Reuters) - A compromise allowing the U.S. Congress to vote on a nuclear deal with Tehran may prompt Iranian negotiators to drive a harder bargain, but does not drastically weaken President Barack Obama's ability to deliver on a final agreement.

For months Obama resisted attempts led by Republicans and some Democrats to open an agreement with Iran to congressional approval. On Tuesday he backed down in the face of mounting bipartisan support for the bill, which gives Congress at least 30 days to review a final deal during which time Obama would be unable to waive or suspend many U.S. sanctions.