Lebanon's president accused Saudi Arabia on Wednesday of detaining the Lebanese prime minister, an escalation in the crisis that followed Saad Hariri's surprised resignation from the kingdom almost two weeks ago.

In comments published on the official Twitter account of the president, Michel Aoun said nothing justifies that Hariri has not returned home so far.

“We consider him detained, arrested” in violation of international laws, Aoun said.

It was the first time Aoun describes Hariri as a detainee. He had previously only questioned the “mysterious” circumstances under which Hariri resigned.

The rhetoric further deepens the crisis with Saudi Arabia, which is a backer of Hariri, a dual Saudi-Lebanese national.

Many believe Hariri's decision was dictated by the Kingdom amid its intensifying feud with Iran over influence in the region. Iran supports Hariri's main rival in Lebanon, Hezbollah, which is also a partner in Hariri's unity government.

Aoun refused to recognise Hariri's resignation and the Lebanese government is carrying on in a business-as-usual manner.

In a quick reaction to Aoun's comments, Hariri tweeted that he was fine and will return to Lebanon as promised. “You will see,” Hariri said without giving a time frame for his return.

Aoun is an ally of Hezbollah but had been close to Hariri before the crisis.

The head of Future TV, affiliated with Hariri's party, says the prime minister is expected back before Sunday, when Arab foreign ministers meet in Cairo in an emergency session at Saudi Arabia's urging.

Riyadh is expected to discuss Iran's rising influence in the region at the meeting, as well as the Lebanese crisis.

Lebanon's Foreign Minister Gibran Bassil said in Paris that Lebanon wants to resolve Hariri's “ambiguous” condition with Saudi Arabia in a “brotherly” fashion.

But Bassil, who is on a European tour seeking support for his country amid the crisis, said that Lebanon also has the option of resorting to international law, without elaborating.

It was not immediately clear if Bassil would attend the Arab League foreign ministers' meeting in Cairo.

Riyadh has asked Saudi nationals to immediately leave Lebanon, with several other Arab countries and allies of the kingdom doing the same.

Many fear punitive Saudi actions against Lebanon over Hezbollah.

France's Foreign Minister is arriving in Saudi Arabia on Wednesday to meet with Hariri and Saudi officials. French President Emmanuel Macron paid a surprise visit to the kingdom last week.

Hariri resigned 12 days ago in a shocking televised address from Riyadh that plunged his country into turmoil.

In a televised interview from the kingdom, Hariri pledged to come back but didn't give a specific date.

His appearance didn't dispel rumors that Hariri was forced to resign and is prevented from returning home.