U.S. President Barack Obama said on Tuesday that he hopes tougher sanctions will be placed on Iran "within weeks” but admitted that oil from the Islamic Republic sways some countries from agreeing to harsher restrictions. The United States wants the current United Nations blacklist to include firms controlled by the Iranian Revolutionary Guards. Speaking alongside French President Nicolas Sarkozy in the White House, President Obama said, "What we said, though, was that there was going to be a timeline to it and that if we had not seen progress by the end of the year it was time for us to move forward on that sanctions track. My hope is that we are going to get this done this spring…. I’m interested in seeing that [sanctions] regimen in place in weeks. “Let's be honest, Iran is an oil producer, and there are a lot of countries around the world that, regardless of Iran's offenses, are thinking that their commercial interests are more important to them than these long-term, geopolitical interests.” China has been the major stumbling block to an American motion for the United Nations Security Council to endorse tougher sanctions. Beijing’s foreign ministry on Tuesday stated it opposes Iranian capability to obtain nuclear weapons, but it has not yet come out in favor of sanctions. China, like Russia, has supplied billions of dollars in investment and equipment in Iran’s nuclear facilities. President Sarkozy said, "The time has come to take decisions." Referring to Germany and Britain, he added, "We will make all necessary efforts to make sure that Europe as a whole engages in the sanctions regimen."