China and Russia believe they were "duped" to allow for military intervention in Libya, said former United Nations Secretary General Kofi Annan on Wednesday, and they are now "very hesitant" to intervene in Syria.

"[China and Russia] did not veto the Libyan intervention. They abstained so that the process could go forward. But they were shocked by the way the mandate was transformed into regime change," said the 2001 Nobel Peace Prize winner, adding that the two countries saw intervention, even through an arms embargo, as a "slippery slope".

Clashes in Libya and Syria erupted in the wake of the Arab Spring revolution last year, with rebel forces fighting against the regimes of Muammar Gaddafi and President Bashar al-Assad respectively.

Related Story: Post-Arab Spring: Can The Arab World Revolutionise Their Economies?

Related News: Western Countries Yet To Fulfil Promise Of Aid To Arab Spring States: Tunisia Central Banker

Air raids to protect Libyan civilians against atrocities committed by Gaddafi's security forces, was sanctioned by a fragile consensus in the UN security council when Russia and China abstained from their veto. Both countries later expressed outrage at the disproportionate use of force by the US, British and French military, which they say extended beyond the UN resolution to impose a defensive no-fly zone.

China and Russia have since used their veto in the UN Security Council to block resolutions aimed at pressuring Syria's Assad. The opposition says that more than 32,000 people have been killed in the clashes between the Assad regime and the rebels. Activists reported more than 160 fatalities on Tuesday's air raids and clashes in Idlib and Damascus.

"They do not want to see Libya repeated in Syria [...] But the fact that one cannot intervene in every situation, does not mean that one should not intervene when one can," said Annan who served as the UN-Arab League special envoy on Syria until he resigned from the post in August this year due to a lack of international cohesion among leaders and diplomats.

His comments came as his successor, Lakhdar Brahimi, urged China to "play an active role in solving the events in Syria" in a meeting with China's foreign minister Yang Jiechi in Beijing, earlier in the day.

Speaking at Singapore's Lee Kuan Yew School of Public Policy, Annan said national sovereignty could not be used as a shield for governments to reject intervention any longer, and that the international community had the responsibility to protect innocent civilians from crimes against humanity.

He said:

We cannot use sovereignty as a reason not to intervene. That some crimes are so shameful that we cannot sit back [...] let me hasten to add that by intervention, I'm not referring to military intervention. Military intervention is the last resort. It has to be political, diplomatic, economic and all sorts of pressure to get them to change their ways and protect their people.

Calling for more consensus to solve the Syrian crisis, Annan urged the international community to cooperate with Iran, given the country's influence in Syria.

"I know some countries have difficulties with Iran. But you don't make peace with your friends, you make peace and reach out to countries that make a difference," he said.

Related Story: Is The Saudi-Iran 'Cold War' About To Heat Up?

Related Story: Can Syria's Rebels Overthrow Assad? - Interview With Jellyfish Operations