"We certainly are not going to, however, sign a piece of legislation that would undermine the ability of the international community to continue to successfully implement the international agreement to prevent Iran from obtaining a nuclear weapon," Xinhua quoted White House spokesman Josh Earnest as saying.
Earlier on Tuesday, US House Republican leaders asked Obama not to take new measures to reinforce the Iran nuclear deal before President-elect Donald Trump's inauguration in January amid reports that the White House was considering such new measures.
"We respectfully request that your administration take no further actions designed to bolster international investment in Iran, or otherwise change or alter the existing sanctions regime within international organisations," House Speaker Paul Ryan, House Majority Leader Kevin McCarthy and House Foreign Affairs Committee Chairman Ed Royce said in a letter to Obama.
The Republicans also informed the Obama administration that legislation to extend the Iran Sanctions Act for another 10 years would soon be sent to him.
"President-elect Trump deserves the opportunity to assess the US policy toward Iran without your administration imposing or implementing additional measures that could complicate the incoming administration's ability to develop its policy," said the letter.
Iran and six world major countries -- the US, Britain, China, Russia, France and Germany -- reached an agreement on the Iranian nuclear issue in July 2015 that puts Iran on the path of sanctions relief but more strict limits on its nuclear programme.