Obama urges Senators to hold off Iran sanctions: White House

WASHINGTON (Reuters) - President Barack Obama warned lawmakers on Tuesday that Iran would make progress in its ability to build a nuclear weapon if there is no diplomatic deal to halt or roll back its nuclear program and urged Congress to hold off on tightening sanctions against Teheran while talks continue. "The president underscored that in the absence of a first step, Iran will continue to make progress on its nuclear program by increasing its enrichment capacity, continuing to grow its stockpile of enriched uranium, installing advanced centrifuges, and making progress on the plutonium track," White House spokesman Jay Carney told reporters at a briefing. (Reporting by Mark Felsenthal, Roberta Rampton, Jeff Mason; Editing by Sandra Maler)