"If this Congress sends me a new sanctions bill now that threatens to derail these talks, I will veto it," Obama said in his State of the Union address before a joint session of Congress.
Obama called on lawmakers to "give diplomacy a chance to succeed," saying that it is diplomacy, backed by pressure.
The P5+1 countries, namely the United States, Britain, France, China, Russia and Germany, reached with Iran a landmark interim deal in November that limits Tehran's nuclear activities in return for eased sanctions by the world powers. The two sides began to implement the deal on Jan. 20, Xinhua reported.
"As we gather here tonight, Iran has begun to eliminate its stockpile of higher levels of enriched uranium. Unprecedented inspections help the world verify, every day, that Iran is not building a bomb," Obama said.
Iran and the P5+1 countries have agreed to resume nuclear negotiations in New York in February, aimed at reaching a final agreement in six months.