U.S. President Barack Obama said on Tuesday at a joint press conference with his French counterpart Nicolas Sarkozy that he expects sanctions on Iran will come in weeks instead of months.

U.S. President Barack Obama (R) and French President Nicolas Sarkozy attend a joint news conference after their meeting in the East Room of the White House in Washington, the United States, March 30, 2010. [Xinhua/AFP Photo]

"My hope is that we are going to get this done this spring," Obama said, adding "I'm interested in seeing that regime in place in weeks."

Obama admitted that a consensus has not been achieved among major powers, but he said the U.S. is working very hard to get the sanctions in effect.

"The time has come to take decisions. Iran cannot continue its mad race," visiting French President Sarkozy said at the press conference, voicing clear support for Obama.

The U.S. and its Western allies have long been accusing Iran of secretly developing nuclear weapons under the guise of a civilian program, and are pressing for a UN resolution to impose new sanctions.

Iran has denied the accusation and stressed its nuclear program is solely for peaceful purposes.

U.S. Secretary of State Hillary Clinton said on Tuesday the U.S. is optimistic the UN Security Council will reach an agreement on what to do about Iran's nuclear program.

China said Tuesday that it has not changed stance on the Iranian nuclear issue, calling for more diplomatic efforts to pursue proper settlement of the issue.

"We will continue to work with all parties towards the solution of the Iranian nuclear issue through diplomatic and peaceful means, " said Chinese Foreign Ministry spokesman Qin Gang at a regular news briefing.