No details of the alleged plot against Saad al-Hariri have been made public.
Uncertainty surrounds Saad al-Hariri’s circumstances, amid rumors he was being held in Riyadh.
President Macron said on November 9 he had had informal contact with Saad al-Hariri, without giving details, while the French foreign minister said France believed Saad al-Hariri was able to move freely.
On November 5, Saad al-Hariri said in a TV broadcast that he was resigning because of the unspecified threat to his life.
In the video statement, Saad al-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.
President Macron is a keen supporter of the 2015 Iranian nuclear deal, which both the Saudis and the Trump administration have heavily criticized.
Before going to Saudi Arabia, Emmanuel 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,” the president added.
However, an official communiqué from his office following the visit did not say Iran was among the matters discussed, Le Monde reported.
Tensions between Saudi Arabia, Iran and Lebanon have soared since Saad al-Hariri announced his resignation.
On November 9, Saudi Arabia and its Gulf allies told their citizens in Lebanon to leave the country immediately. The move came after Saudi Arabia accused Iran of “direct military aggression”, saying it supplied a missile which it says was fired by Hezbollah at Riyadh from Yemen on November 5.
Iran has dismissed Saudi Arabia’s allegations as “false and dangerous”.
Correspondents say Saad al-Hariri’s sudden departure plunges Lebanon into a new political crisis and raises fears that it may be at the forefront of the regional rivalry between Shia power Iran and Sunni stronghold Saudi Arabia.
Following the statement on November 4, Iranian politicians lined up to denounce Saad al-Hariri’s assertions.
Hussein Sheikh al-Islam, adviser to Iranian Supreme Leader Ayatollah Ali Kahmenei, said: “Hariri’s resignation was done with planning by [President] Donald Trump and Mohammed bin Salman, the Crown Prince of Saudi Arabia.”
Iranian foreign ministry spokesman Bahram Qasemi, quoted by the official Irna news agency, said Saad al-Hariri’s departure was aimed at creating tension in Lebanon and the region.
Bahram Qasemi said Saad al-Hariri had repeated “unrealistic and unfounded accusations” and had aligned himself with “those who want ill for the region”, singling out Israel, Saudi Arabia and the US.
Saad al-Hariri, whose family is close to Saudi Arabia, has been prime minister since December 2016, after previously holding the position between 2009 and 2011.
His father, Rafik al-Hariri was killed by a bomb in 2005 in an attack widely blamed on the Iran-backed Shia movement Hezbollah, which wields considerable power in Lebanon.