The committee discussed the situation in Afghanistan
Prime Minister David Cameron has chaired the first meeting of the new National Security Council.
The body, made up of senior ministers, military chiefs and the heads of the secret service, discussed the military situation in Afghanistan.
It was also briefed on the UK's wider strategic and security position.
Deputy PM Nick Clegg, Chancellor George Osborne and Foreign Secretary William Hague were among those who attended the Downing Street meeting.
The council was set up on Wednesday to co-ordinate the efforts of government departments and agencies to safeguard UK security.
A Downing Street spokesman said: "The prime minister this evening chaired the first meeting of the newly established National Security Council.
"The prime minister began the meeting by paying a full tribute to the UK's armed forces and expressed his personal admiration and gratitude for their dedication and sacrifice.
"He then received briefings on the political and military situation in Afghanistan, including from his new National Security Advisor, Sir Peter Ricketts, and from the Chief of the Defence Staff [Sir Jock Stirrup]. The prime minister was then updated on the wider UK security situation."
The other figures who attended were: Home Secretary Theresa May, Defence Secretary Liam Fox, International Development Secretary Andrew Mitchell, Security minister Dame Pauline Neville-Jones, Cabinet Office minister Francis Maude, Cabinet Secretary Gus O'Donnell, the chairman of the Joint Intelligence committee, the director-general of the Security Service, Sir John Sawers, the head of MI6, who is identified on the name label in front of him only as "C", and the director of GCHQ.