Prime Minister David Cameron has described the violence in Syria as "appalling and criminal butchery", during questioning by senior MPs.
He faced the Commons Liaison Committee on 6 March 2012, and answered questions on UK policies towards Iran and Syria.
The prime minister repeated criticism of Russia and China for blocking a UN Security Council resolution condemning the actions taken by the Bashar al-Assad regime, and said he had raised the issue with newly re-elected Russian president Vladimir Putin.
He added that "transition from the top" would be the best way to ensure a more stable future in Syria.
The committee is made up of the chairs of the House of Commons select committees and takes evidence from the prime minister approximately two or three times a year.
The chair of the Foreign Affairs Committee, Richard Ottaway, questioned Mr Cameron on whether the UK could live with an Iran that had nuclear capabilities.
The prime minister replied that he did not want to "see that come about", and told the committee "there is a greater sense now that the world wants to send a very clear message about what is and isn't acceptable".
However, he warned against any unilateral action by Israel.
Mr Cameron also faced questions on the government's public sector reform programme.
The chair of the Public Accounts Committee, Margaret Hodge, said that it would be more difficult for taxpayers to follow how their money is being spent, "given the literally thousands of independent units delivering public services" - such as NHS foundation trusts and academy schools.
However, the prime minister said his reform agenda was increasing transparency, with all public sector contracts over £10,000 and any government spending of more than £25,000 being published.