French President Emmanuel Macron has paid an unscheduled visit to Saudi Arabia amid an escalating crisis between the kingdom and Lebanon.
His trip comes days after Lebanese PM Saad Hariri resigned while in Riyadh, saying he feared for his life.
Foes Saudi Arabia and Iran have accused each other of fuelling instability in Lebanon and the wider region.
Mr Macron and Saudi officials also discussed the crisis in Yemen, where Riyadh is leading a war against rebels.
France has historical ties with Lebanon, as it was given the mandate to run the country before Lebanese independence during World War Two.
The French president was in the United Arab Emirates on Thursday to open the Louvre Abu Dhabi, a spin-off of the famous Paris art museum.
Ahead of his two-hour visit to Riyadh, Mr Macron said all Lebanese officials should live freely, "which means having a very demanding stance on those who could threaten any leader".
No details of the alleged plot against Mr Hariri have been made public.
Uncertainty surrounds Mr Hariri's circumstances, amid rumours he was being held in Riyadh.
Mr Macron said on Thursday he had had informal contact with Mr Hariri, without giving details, while France's foreign minister said France believed Mr Hariri was able to move freely.
Mr Hariri said in a TV broadcast on Saturday that he was stepping down because of the unspecified threat to his life.
In the video statement, Mr Hariri also attacked Hezbollah, which is politically and militarily powerful in Lebanon, and Iran.
There are fears Lebanon could become embroiled in a wider regional confrontation between major Sunni power Saudi Arabia and Shia-dominated Iran.
Mr Macron is a keen supporter of the 2015 Iranian nuclear deal, which both the Saudis and the Trump administration have heavily criticised.
Before going to Saudi Arabia, Mr Macron said that he had heard "very harsh opinions" on Iran from Saudi Arabia, which did not match his own view. "It is important to speak with everyone," he added.
But an official communiqué from his office following the visit did not say Iran was among the matters discussed, French newspaper Le Monde reported.
Tensions between Saudi Arabia, Iran and Lebanon have soared since Mr Hariri announced his resignation.
On Thursday, Saudi Arabia and its Gulf allies told their citizens in Lebanon to leave the country immediately. It came after Riyadh accused Iran of "direct military aggression", saying it supplied a missile which it says was fired by Hezbollah at Riyadh from Yemen on Saturday.
Iran has dismissed the Saudi allegations as "false and dangerous".