Hariri, who threw Lebanon into political crisis by reading out his resignation on Nov. 4 from Riyadh, gave his first public remarks since then in an interview late on Sunday, saying he planned to return within days.
He suggested he could even withdraw his resignation, provided the Shi'ite group Hezbollah - allied to Saudi Arabia's regional rival Iran - renounces interference in conflicts across the Middle East.
The crisis has thrust tiny Lebanon - where Sunni, Shi'ite, Christian and Druze groups with backing from regional powers fought a 1975-1990 civil war - to the forefront of the rivalry between Riyadh and Tehran being played out on battlefields from Syria to Yemen.
Aoun has said he believes Hariri does not have free control over his own movements while in Saudi Arabia, and that this casts doubt on any statements Hariri makes. Nevertheless those close to Aoun said the president welcomed Hariri's comments.
'President Aoun expressed his pleasure at Hariri's announcement of his return to Lebanon soon,' a source said.
Lebanon';s Prime Minister Saad al-Hariri at the governmental palace in Beirut, Lebanon, Oct. 24, 2017.
Aoun said that Hariri was 'leaving all doors open including rescinding his resignation', according to one of a group of visitors who met Aoun. The visitors declined to be identified while discussing the closed-door conversations.
The visitors quoted Aoun as saying that Hariri's remarks showed that the political deal underpinning Lebanon's coalition government - which includes both Hariri's Sunni party and the heavily armed Shi'ite movement Hezbollah - still stands.
Aoun has been convening high level meetings with Lebanese politicians and diplomats since Hariri stepped down, and the visitors said the president believed that Hariri's comments showed such efforts were working.
Silence From Hezbollah
Nearly 24 hours after Hariri's interview, which appeared on a TV station he owns, Hezbollah had still not commented on his remarks. But so far during the crisis Hezbollah has backed the approach taken by its political ally Aoun, a veteran Christian politician.
Hezbollah's allies in Iran said Hariri's remarks gave hope he would return to Lebanon.
In his resignation speech Hariri, whose father, also a former prime minister, was killed by a bomb in 2005, said he feared assassination. He said in his interview eight days later that he was free to leave Saudi Arabia but that his movements were also guided by concern for his family's safety.
Hariri's Future Movement political party said on Monday it saw his plan to return to Beirut within days as a 'good sign' and a step on the road to repairing Lebanon's foreign relations.
In a televised statement, Future Movement lawmaker Ammar Houri said it supported Hariri's statement that Lebanon should stay out of regional conflicts and reject Iran's interference.
Saudi Arabia denies that it coerced Hariri into resigning or has kept him from leaving. It has accused Lebanon of declaring war on it because of Hezbollah, and has advised Saudi citizens to leave Lebanon. Hezbollah says it was the Saudis who have declared war on Lebanon.
Hariri's comments encouraged a recovery on Monday in Lebanese dollar bonds, which slumped last week.