Talks have resumed over Iran's nuclear program as a deadline for a draft agreement draws closer. Officials have been negotiating with Iran to wind back its program, in hopes of preventing it developing nuclear weapons.
US Secretary of State John Kerry met with his Iranian counterpart Mohammad Javad Zarif in the Swiss town of Lausanne on Thursday.
Kerry is expected to urge Iran to agree to the draft framework, due by Tuesday, in exchange for international sanctions being eased against the Arab state.
A State Department official traveling with Kerry said the US was cautiously optimistic about a deal.
"We can see a path forward here to get to an agreement (…) that doesn't mean we'll get there," he said. "March 31 is a real date and it is an important one."
The March and June targets were set after a second round of talks in November failed to realize turning a 2013 agreement into a comprehensive accord.
Both US President Barack Obama and Iran's Ayatollah Ali Khameini have said they hope not to have to have a third round of talks.
Iran's nuclear chief Ali-Akbar Salehi told AFP he was positive about reaching a deal, despite interference from those opposed to one.
"On the whole I am optimistic (…) but there are those who have an interest in more troubles. They are trying to make sure there is no deal," he said.
Leaders from six world powers - the US, Britain, Germany, Russia, China and France - are aiming to have an outline of an agreement agreed upon by the end of March, before a final version is made in June of this year.
However the US, United Nations and European Union say sanctions would be quickly reinstated if Iran violates any of the deal's terms, something Iran disagrees with.
The agreement would be a historic achievement for the West and Iran, ending a 12-year standoff over the nation's nuclear program.
Air strikes over Yemen
It comes as US-ally Saudi Arabia launched air strikes on Iran-backed fighters in neighboring Yemen, sparking an angry reaction from Tehran.
Saudi Arabia said the action was designed to reinstate what it called the legitimate government of President Abed Rabbo Mansour Hadi, who fled Yemen's capital Sanaa last month after it was captured by rebel forces.
Iran's foreign minister warned there could be no positive outcome from the strikes.
"Military action from outside of Yemen against its territorial integrity and its people will have no other result than more bloodshed and more deaths," he said.
The head of the Iranian parliament's national security and foreign policy committee, Alaedin Boroujerdi, went further, accusing the US of helping with the attacks.
"America, which leads the fire mongering in the region, has supported this act and no doubt Saudi Arabia and some countries in the Arab cooperation council would not get involved without America's permission," Boroujerdi said.
Although neither diplomat would comment on the situation before discussions began, a conference call was held between Kerry and Gulf ministers concerning the Yemen crisis.
A senior US official said the during the call Kerry thanked the coalition for launching military strikes against the Houthis, and highlighted Washington's role in providing intelligence and support for this latest round of action.
A 'dangerous' agreement
The re-election of Israeli Prime Minister Benjamin Netanyahu, who has expressed very public opposition to any agreement with Iran, has also upped the pressure on the United States.
On Wednesday, Netanyahu said his feelings towards the deal remained unchanged.
"We will continue to act to prevent the emerging agreement with Iran, an agreement which endangers us, our neighbors and the world," he said.
The issue has strained already troubled ties between the US and Israel, despite Netanyahu pledging to "preserve our (Israel's) alliance" with the US.
an/msh (AFP, AP, Reuters)