Beirut, Lebanon(CNN) Lebanese Prime Minister Saad Hariri is being "held captive" in Saudi Arabia in an "act of aggression" against Lebanon, according to the country's President.
President Michel Aoun dubbed Hariri a hostage in the most strongly worded statement since the Prime Minister quit his post earlier this month from the Saudi capital of Riyadh.
"What happened wasn't the resignation of a government, but an act of aggression against Lebanon, its independence and dignity, and against relations between Saudi Arabia and Lebanon," Aoun said Wednesday, according to a statement released his office.
"We do not accept that (Hariri) remain hostage, and we do not know the reasons for his captivity."
"Nothing justifies Prime Minister Saad Hariri's not returning to the country in 12 days. We therefore consider him detained and held captive, which violates the Vienna Convention and the Universal Declaration of Human Rights."
"It is not possible for us to make a decision about this resignation from abroad. (Hariri) should return to Lebanon and submit his resignation so that we may refer to it and probe its reasons and ways to solve it," Aoun said, according to the statement.
Shortly after Aoun's remarks, Hariri tweeted that he was "very, very well" and that he would soon return.
"I want to reiterate that I am very, very well and I will return if God wills it to the beloved Lebanon just as I promised. You'll see," Hariri tweeted.
On Tuesday, Hariri tweeted that he hoped to return "in the next two days."
Hariri resigned in an address from Riyadh on November 4, saying his life was in danger. He has not been back to Lebanon since, fueling speculation that he is being held against his will.
A high-level ministerial source told CNN last week that Hariri's closest allies "have no idea what's going on," and that members of his own political party believe Saudi Arabia is "restricting" his movements.
His announcement plunged Lebanon into a political crisis and stoked fears of conflict between the Saudi-backed faction of the country's government and the Iranian-backed Shia militant group Hezbollah, with which Hariri shares power.
So far Lebanon's rival political factions have called for calm, and made public statements asking for Hariri's return.
France called Tuesday for Hariri be allowed to go home and urged all sides to ratchet down tensions.
In an address to the French National Assembly, French Prime Minister Edouard Philippe said: "The goal is for Saad Hariri to be able to return home freely to clarify his situation in accordance with the Lebanese constitution. It's also important that all Lebanese parties agree to respect civil peace."