Iran is willing to work with the US to help defeat Islamic State (IS) militants, a senior Iranian government source has told Reuters.
However, Tehran would like to see more flexibility over its nuclear programme in exchange for helping Western powers tackle IS.
"Iran is a very influential country in the region and can help in the fight against the ISIL (IS) terrorists ... but it is a two-way street. You give something, you take something," the source was quoted as saying.
However, a Western diplomatic source said the countries negotiating over Tehran's nuclear programme were "determined not to bring the other subjects to the nuclear negotiations table".
A British woman who went missing while travelling on a yacht off the coast of Mexico has been found dead.
The Foreign Office confirmed that a body, believed to be that of Simone Wood, was discovered following a search operation launched in the wake of Hurricane Odile.
Ms Wood's partner Paul Whitehouse is still missing, Associated Press reported.
"We can confirm the death of a British national, reported missing along with another British national earlier this week off the coast of Mexico," a Foreign Office spokeswoman said.
An intruder who made it into the White House after breaching security was allegedly armed with a knife, a court document has revealed.
Oscar Gonzalez, 42, climbed over the fence and made it through an entrance to the White House on Friday night - just minutes after President Obama and his daughters had left the presidential residence.
Gonzalez was charged with unlawfully entering a restricted building or grounds while carrying a "deadly or dangerous weapon," the US Attorney's Office said.
The Secret Service previously said Gonzalez was unarmed.
Security at the White House will be increased after a man managed to jump over a fence and enter the doors of the building, the Secret Service said.
The director of the Secret Service Julia Pierson has ordered the "immediate enhancement of officer patrols and surveillance capabilities along the Pennsylvania Avenue fence line".
An internal investigation into security procedures is also under way following the breach, the service added.
The White House was partially evacuated on Friday night after Omar J Gonzalez evaded security and entered the doors of the executive mansion.
The Secret Service said agents displayed "tremendous restraint and discipline" in dealing with Gonzalez.
The wife of British hostage Alan Henning has pleaded with Islamic State militants not to "allow the world to see a man like Alan dying".
Ina statement released through the Foreign Office, Mr Henning's wife Barbara said she has sent messages to IS urging them to release her husband but has received no response.
I am Barbara Henning the wife of Alan Henning.
Alan was taken prisoner last December and is being held by the Islamic State.
Alan is a peaceful, selfless man who left his family and his job as a taxi driver in the UK to drive in a convoy all the way to Syria with his Muslim colleagues and friends to help those most in need.
When he was taken he was driving an ambulance full of food and water to be handed out to anyone in need.
His purpose for being there was no more and no less. This was an act of sheer compassion.
I cannot see how it could assist any State's cause to allow the world to see a man like Alan dying.
I have been trying to communicate with the Islamic State and the people holding Alan. I have sent some really important messages but they have not been responded to.
I pray that the people holding Alan respond to my messages and contact me before it is too late.
When they hear this message I implore the people of the Islamic State to see it in their hearts to release my husband Alan Henning.
The wife of British hostage Alan Henning has called on "the people of the Islamic State to see it in their hearts to release my husband", describing him as a "peaceful, selfless man".
Police in Thailand said they still have not "come up with the exact number of the suspects" following the brutal murders of two British tourists, but confirmed they are looking for more than one.
Six days after the bodies of Hannah Witheridge, 23, and David Miller, 24, were found with severe head wounds on a beach on the island of Koh Tao.
A spokesman for Royal Thai Police would not confirm that DNA from Miss Witheridge's body reportedly matched that of two Asian men.
Fighting in Ukraine is continuing and the truce there is a ceasefire "in name only", Nato's top military commander said. "The situation in Ukraine is not good right now," U.S. Air Force General Philip Breedlove told reporters in Vilnius.
"Basically, we have ceasefire in name only," he added.
Ukraine's government and pro-Russian rebels have agreed to strengthen an earlier ceasefire agreement in eastern Ukraine.
More than 3,000 people have been killed since fighting began in the region five months ago.
A search is underway for a British couple missing after a hurricane hit the coast of Mexico.
Friends of Paul Whitehouse and Simone Wood said they were on a yacht which capsized, after Hurricane Odile swept through La Paz last Sunday.
ITV News reporter Sejal Karia reports:
At least 36 people were killed by the Islamist militant group Boko Haram in Nigerian town of Mainok.
Security forces said at least 23 civilians were killed in the attack on a local market.