United States President Barack Obama and visiting British Prime Minister David Cameron on Wednesday pledged to prevent Iran from acquiring nuclear weapons, but noted that there is still time and space for diplomatic options which is shrinking.
"I think they (Iran) should understand that because the international community has applied so many sanctions, because we have employed so many of the options that are available to us to persuade Iran to take a different course, that the window for solving this issue diplomatically is shrinking,"
Obama warned Iran during a joint news conference with Cameron at the Rose Garden of the White House.
Obama said he was determined not simply to contain Iran that is in possession of a nuclear weapon. "I am determined to prevent Iran from getting a nuclear weapon, in part for the reasons....it would trigger a nuclear arms race in the most dangerous part of the world".
Cameron, who is here on a state visit, said Obama's tough, reasonable approach has united the world behind unprecedented sanctions pressure on Iran.
"Britain has played a leading role in helping to deliver an EU-wide oil embargo. Alongside the financial sanctions being led by America, this embargo is dramatically increasing the pressure on the regime," he said.
Obama said a nuclear Iran "would raise nonproliferation issues" that would carry significant risks to American national security interests. Obama argued that it would embolden terrorists in the region who might believe that they could act with more impunity if they were operating under the protection of Iran".
The president said therefore it is not an issue that is simply in one country's interests or two countries' interests. "This is an issue that is important to the entire international community".
However, he underlined his determination to "do everything we can to resolve this diplomatically".
In response to a question, Obama said ultimately there has to be "somebody on the other side of the table who's taking this seriously". "...and I hope that the Iranian regime understands that, that this is their best bet for resolving this in a way that allows Iran to rejoin the community of nations and to prosper and feel secure themselves," Obama said.
Cameron said they are serious about the talks that are set to resume, but "the regime has to meet its international obligations".
"If it refuses to do so, then Britain and America, along with our international partners, will continue to increase the political and economic pressure to achieve a peaceful outcome to this crisis," he said.
"As the (US) president and I have said, nothing is off the table. That is essential for the safety of the region the wider world," Cameron said.
Obama said the US and its partners have mobilized the international community with greater unity than we've ever seen.
"Those sanctions are going to begin to bite even harder this summer. And we're seeing significant effects on the Iranian economy. So they understand the seriousness with which we take this issue. They understand that there are consequences to them continuing to flout the international community," he said.
Obama said he has sent a message very directly Iran that it needs to "seize this opportunity of negotiations with the P-5 plus one to avert even worse consequences for Iran in the future".
He said in the past there's been a tendency for Iran in these negotiations with the P-5 plus one "to delay, to stall, to do a lot of talking, but not actually move the ball forward".