US President Barack Obama says he hopes new UN sanctions over Iran's nuclear programme will be in place "in weeks".
The US and France have vowed to work together on the push, after talks between Mr Obama and the French leader, Nicolas Sarkozy, in Washington.
Western powers suspect Iran is seeking to develop a nuclear arms capability. Tehran denies this.
It says its atomic programme is entirely peaceful.
Speaking at a press conference, Mr Obama said the move had backing from the international community.