* First French leader to meet Iranian president since 2005
* Hollande tells Rouhani wants quick results on nuclear talks
* Wants mention of Chapter 7 in UN Syria resolution
By John Irish
UNITED NATIONS, Sept 24 (Reuters) - French President Francois Hollande became the first Western leader to meet new Iranian President Hassan Rouhani on Tuesday after warning that Paris expects "concrete gestures" by Iran to show it will give up a military nuclear program.
France has been a strong advocate of sanctions to pressure Iran over its nuclear program but has been cautious in its statements since Rouhani, a relative moderate, was elected in June.
Hollande, who exchanged handshakes with Rouhani at the United Nations in mid-afternoon - the first between leaders of the two countries since 2005 - told the U.N. General Assembly that while he was encouraged by the words of the new Iranian government, he now wanted acts to follow.
"France expects of Iran concrete gestures which will show that this country renounces its military nuclear program even if it clearly has the right to pursue its civilian program," Hollande said in an address to the assembly before going into a meeting with Rouhani.
"This is why I have made the choice to engage in direct and open dialogue with President Rouhani," Hollande said. "But I will also say ... I am in favor of dialogue, but just as strongly I am firm on the issue of nuclear proliferation."
After a 40-minute meeting, a French aide said the encounter had been polite and courteous, with the two men discussing the crisis in Syria, Lebanon and Iran's nuclear program.
"The French president said he had taken note of the overtures by his counterpart ... and on the nuclear issue he said that there needed to be quick results within the 5+1 framework," the aide said.
Since Rouhani was elected president, the centrist cleric has called for "constructive interaction" with the world, a dramatic shift in tone from the strident anti-Western and anti-Israeli rhetoric of his predecessor, Mahmoud Ahmadinejad.
The United States and its allies suspect Iran is seeking nuclear bomb-making capability despite Tehran's insistence that its atomic program has only peaceful aims. Rouhani has vowed that his government would never develop nuclear weapons.
Tough sanctions imposed by Washington and the United Nations over the issue have taken a severe toll on Iran's economy.
Hollande is the first Western leader of the P5+1 nations - United States, Russia, China, Britain, France and Germany - to meet Rouhani, and the first French leader to meet an Iranian president since Jacques Chirac met Mohammad Khatami in 2005.
Hollande also discussed the crisis in Syria with Rouhani, as he hopes to persuade Tehran to loosen its support for President Bashar al-Assad and accept the terms of the proposed Geneva 2 peace conference that calls for a transitional authority in the civil war-torn country, something Iran has so far not backed.
The French aide said Rouhani had told Hollande he wanted the war to end and that he was open to the idea of Geneva 2.
Hollande earlier told the United Nations that too much time had been wasted trying to end the 2-1/2-year civil war in Syria, which the United Nations says has killed more than 100,000 people.
"We must ensure that this war ends. It is the deadliest war since the beginning of this century. The solution is a political one and too much time has been lost," he said.
Reiterating calls from his foreign minister on Monday, Hollande said he wanted a U.N. Security Council resolution that would keep close to the terms of a U.S.-Russia deal to eradicate Syria's chemical weapons. He said he would not demand the resolution be placed under the U.N.'s Chapter 7, although it should make reference to it.
"France wants a resolution that can foresee coercive measures, that means under Chapter 7 in case the Syrian regime does not comply with its commitments," Hollande told a news conference. "The absence of any reference to Chapter 7 would deprive the United Nations of any credibility to act."
Russia accused the West on Sunday of trying to exploit the deal between Moscow and Washington to push through a council resolution issued under Chapter 7 of the U.N. charter, which could authorize sanctions or military intervention if the Syrian government reneges on its commitments.
According to the Geneva agreement, the Security Council would have to adopt a second resolution to punish Syria for any non-compliance with the U.S.-Russia plan.
Russia and China have blocked three U.N. resolutions meant to pressure Assad during Syria's civil war.
In a clear sign of frustration with Moscow's continued stance, Hollande also called on the five permanent members of the Security Council to collectively drop their right to veto resolutions in cases that included crimes against humanity.