U.S. Secretary of State John Kerry is due to travel to Vienna later on November 20 to join high-level nuclear negotiations with Iran as a deadline for an agreement approaches.
State Department spokeswoman Jen Psaki says Kerry will meet with the U.S. negotiating team in Vienna in the evening before talks with others.
Psaki spoke shortly after Kerry held talks in Paris with the Saudi Foreign Minister Saud Al Faisal and before he was to see his French counterpart Laurent Fabius.
Kerry arrived in Paris earlier November 20 after two days of Iran-related meetings in London.
International negotiators meeting in Vienna are trying to seal a deal on Iran's nuclear program ahead of a commonly agreed November 24 deadline.
Western officials have said in recent days that big gaps remained and it was unclear whether a deal would be agreed.
Iran's Foreign Minister Mohammad Javad Zarif said upon arrival in Vienna on November 18 that an agreement was "possible."
But he warned that if a deal cannot be reached it will be because the six nations negotiating with Iran -- the United States, Russia, China, Britain, France, and Germany -- asked for too much.
Zarif told Iranian media, "If, because of excessive demands...we don't get a result, then the world will understand that the Islamic Republic sought a solution, a compromise and a constructive agreement and that it will not renounce its rights and the greatness of the nation."
The target of the talks is a deal that would curb Iran's nuclear program and eliminate concerns it could developing atomic weapons, and lead to the removal of UN and Western sanctions that have hurt Iran's oil-dependent economy and sent inflation and unemployment soaring.
In months of negotiations since an interim deal was reached last November, a major sticking point has been over Iran's refusal to substantially cut the size and output of centrifuges that can enrich uranium levels high enough to be used in nuclear warheads.
Iran denies Western accusations that its nuclear program aims secretly at developing a nuclear weapon, saying it is meant only for peaceful purposes such as power generation.
But the head of the International Atomic Energy Agency (IAEA) said on November 20 that Tehran should quickly answer remaining questions on alleged nuclear weapons projects.
Director General Yukiya Amano told the IAEA's 35-nation Board of Governors in Vienna, "I call upon Iran to increase its cooperation with the agency and to provide timely access to all relevant information, documentation, sites, material and personnel."
An IAEA report on November 7 said Iran was failing to address the accusations.
With reporting by AFP and dpa