(CNN) -- Bipartisan legislation was introduced in the U.S. Senate on Thursday that would authorize new economic sanctions on Iran if it breaches an interim agreement to limit its nuclear program or fails to strike a final accord terminating those ambitions. The proposal led by Foreign Relations Committee Chairman Robert Menendez, a New Jersey Democrat, and Mark Kirk, an Illinois Republican, emerged despite Obama administration appeals for Congress to defer pursuing new sanctions with diplomatic efforts ongoing. The White House said new sanctions would undermine those delicate efforts on the global stage and President Barack Obama would veto the legislation if Congress were to approve it now.
@highlight
Bipartisan proposal considers diplomatic effort under way around Iran nuclear issue
@highlight
Legislation would give President Barack Obama more time to pursue diplomacy
@highlight
Sanctions would kick in early if Iran violates current international nuclear deal
@highlight
The Obama administration doesn't want sanctions bill; threatens veto
"Secondly, the President should want these sanctions as a weapon to hold over the @placeholder, so I don't see why the President is so opposed to these sanctions."