President Obama said Tuesday the deadline for sanctions against Iran is fast approaching and that the United States and its allies have extended a hand that has been rejected.

“I think that we have bent over backwards to say to the Islamic Republic of Iran that we are willing to have a constructive conversation about how they can align themselves with international norms and rules and reenter as full members of the international community,” President Obama said at a press conference.

The issue of sanctions against Iran has been in the works since 2009 with President Obama even laying out an end-of-the-year deadline with his French and British counterparts, but Iran continues to block international observers who want to take stock of its uranium enrichment program, a step on its way to possibly becoming a nuclear nation.

“Despite their posturing that their nuclear power is only for civilian use, they in fact continue to pursue a course that would lead to weaponization,” Obama said. “And that is not acceptable to the international community, not just to the United States.”

Earlier on Tuesday, Defense Secretary Robert Gates who was in Paris for meetings, said he hopes resolution can be reached with Iran before military action is needed. "Everybody's interest is in seeing this issue resolved without a resort to conflict," Gates said. "The key is persuading the Iranian leaders that their long-term best interests are best served by not having nuclear weapons, as opposed to having them. And so I think that an approach along these lines, as long as the international community is seen pressing vigorously to resolve this problem, my hope is we will then be able to keep this in economic and diplomatic channels."

These diplomatic channels also include China, a nation which in the past has cooperated with the United States on the issue of Iran, but has recently disappeared from negotiations. Experts warn the lack of Chinese participation could not only jeopardize talks on Iran, but also have a global effect. “Are we going to have China as a responsible partner or is China going to be cheating and undermining?,” says Jon Alterman of the Center for Strategic and International Studies. “And I think what Iran does to me, is it makes me worry that China is going to do the cheating and undermining route.”

President Obama said he remains optimistic the Chinese will work with the U.S., but seemed more hopeful Russia would also help on the nuclear issue.

“How China operates at the Security Council as we pursue sanctions is something that we're going to have to see,” Obama said. “One thing I'm pleased about is to see how forward-leaning the Russians have been on this issue. I think they clearly have seen that Iran hasn't been serious about solving what is a solvable dispute between Iran and the international community. We are confident right now that the international community is unified around Iran's misbehavior in this area.”

But even if the President is hopeful Iran will cooperate, his administration has still left all options on the table.“They have made their choice so far, although the door is still open. And what we are going to be working on over the next several weeks is developing a significant regime of sanctions that will indicate to them how isolated they are from the international community as a whole,” Obama said.