US Secretary of State John Kerry on Wednesday ruled out a military solution for Syria, saying its conflict does not resemble Libya's while calling for a settlement based on last year's Geneva peace plan.

"This is not Libya. It is very different in many, many ways," Kerry told reporters in Kuwait City in response to a question on why there had been no military intervention in Syria as during Libya's 2011 armed uprising.

Kerry made the remarks after holding talks with Kuwaiti Foreign Minister Sheikh Sabah Khaled al-Sabah.

He said that unlike Libya, foreign forces including the Lebanese Shiite movement Hezbollah had intervened in Syria, while Russia was supplying the regime with arms.

Kerry warned the fighting in Syria could lead to the destruction of the state, the collapse of the army and a total breakdown of a sectarian strife for many years to come.

"That becomes far more dangerous for all the region because it will empower extremists... and the potential increase of terrorism," which is not acceptable to the civilised world.

"There is no military solution here... We need to reach out for a diplomatic solution" through negotiations in the Swiss city of Geneva, said Kerry.

Such talks would seek to implement the "Geneva 1 communique which requires a transition government in a neutral environment," he added, referring to the 2012 peace plan backed by Russia.

The United Nations said Tuesday that Kerry and Russian Foreign Minister Sergei Lavrov are to meet next week in Brunei to discuss how to move forward towards a new international peace conference for Syria.

Kerry also called on Iran to pull its troops out of Syria and for Hezbollah to return to Lebanon.

His Kuwaiti counterpart Sheikh Sabah called for the "need to find a peaceful solution and send humanitarian aid to the Syrian people".

On Tuesday, Gulf powerhouse Saudi Arabia urged global action to bring an end to the regime of Syrian President Bashar al-Assad, telling Kerry the civil war had turned into "genocide".

"The kingdom demands a clear, unequivocal international resolution that bans any sort of weapons support for the Syrian regime and declares null and void the legitimacy of that regime," Foreign Minister Saud al-Faisal told a joint news conference with the US diplomat.