UK Edition
Barack Obama used nuclear 'red phone' to warn Putin about Russian hacking of US election
President Barack Obama used the "red phone" system set up to avert nuclear war to issue a stark warning to Vladimir Putin over Russian hacking of the US election.
Mr Obama delivered the message to the Russian president in October stating that further cyber attacks would be considered in the same way as "armed conflict," NBC News reported.
The US president had already confronted Mr Putin personally when they met on the sidelines of the G20 summit in China in September.
But the "red phone" warning went further. In it Mr Obama said: "International law, including the law for armed conflict, applies to actions in cyberspace. We will hold Russia to those standards."
The hotline was set up as an emergency means of direct communication between Washington and the Kremlin in 1963 during the Cold War.
It was established in the wake of the Cuban Missile Crisis when messages between the two superpowers took many hours to reach each other.
There were never actual red telephones and the system originally used teletype, then fax machines. From 2008 it used secure email and that was how Mr Obama's message was delivered.
The system has previously been used to communicate about major events such as the Russian invasion of Afghanistan in 1979 and the US invasion of Iraq in 2003.
In 2013 it was agreed that major cyber security incidents should also be discussed on the secure hotline.
The US warning in October was the first time it has been used relating to a cyber incident, NBC News reported.
Doing so was intended to signify how seriously the Obama administration viewed Russian interference.
Russian hackers linked to the Kremlin have been blamed for stealing and releasing Democratic Party emails with the intention of undermining Hillary Clinton.
US intelligence agencies have accused Mr Putin of personal involvement.
The Obama administration claimed the decision to use the "red phone" system worked as there appeared to have been no Russian hacking on Election Day itself in November.
A White House official said: "This action was part of our ongoing, rigorous efforts to press the Russian government to halt the actions of those responsible for these cyber attacks."