WASHINGTON, March 21 -- U.S. President Barack Obama, in an interview published on Saturday, voiced optimism about a nuclear deal to be reached with Iran within weeks.

"Our goal though is to get this done in a matter of weeks, not months," the president told The Huffington Post.

He said, however, Tehran had not made "concessions" needed for a final accord to be struck in its negotiations with the United States, Britain, France, Russia, China plus Germany, a group collectively known as P5+1.

"But they have moved, and so there's the possibility," Obama said, adding "There is no deal until everything is worked out, and I think that it's premature to suggest that there is a draft out there."

The P5+1 group suspended on Friday their latest round of talks with Iran held in the Swiss city of Lausanne for the Iranians to celebrate Nowruz, or the Persian New Year, with more talks to be resumed next week with a view to reaching a framework deal by the end of this month.

"Negotiations have broken for a week because of the Nowruz holidays inside of Iran, which gives time for us to make sure that everybody within the P5+1 is comfortable with the current positions that are being taken," said Obama.

Obama's words followed Iranian President Hassan Rouhani's remarks that a final deal on Iran's disputed nuclear program is possible with some progress achieved in recent talks.

"Reaching a final agreement is possible," Rouhani was quoted as saying by official IRNA news agency.

However, he said despite some progress made in the latest round of talks in Lausanne, gaps remain on certain issues.

Talks will become more difficult when resumed in the next few days, Rouhani said, adding that both Iran and world powers will have to compromise in taking the final steps toward a comprehensive deal.