Hariri is part of a joint government that includes Hezbollah, the Iran-backed militant group, and he used his resignation speech to criticize that group and Iran.
"Due to the circumstances in the Lebanese Republic, the kingdom asks its citizens who are visiting or residing" there to leave as soon as possible, a Foreign Ministry source quoted by the news agency said. Two top Lebanese government officials have accused Riyadh of holding Hariri against his will.
State Department spokeswoman Heather Nauert also said the U.S. charge d'affaires in Riyadh met on Wednesday with Saad al-Hariri, who resigned as Lebanese prime minister while in Saudi Arabia.
The US already backs Saudi Arabia in this battle.
Under the terms of the so-called National Pact adopted then, a Maronite Christian is supposed to be the country's president, a Sunni Muslim holds the post of prime minister and a Shiite Muslim serves as speaker of parliament.
Saad al-Hariri resigned, using a television interview broadcast from Saudi Arabia to declare he fears an assassination plot while also criticising Iran.
Israeli News Channel 10 published a leaked diplomatic cable which confirmed that Israel is somehow somewhere running a propaganda agenda with Saudi Arabia to start a war with Iran and Hezbollah.
Macron also says the missile fired by Yemen's Shiite rebels over the weekend at Riyadh was "obviously" an Iranian missile.
"I rule out the possibility of any military confrontation in Lebanon as the situation here can not stand a conflict between two regional giants", said Chinchinian, noting that Lebanon has already suffered a 15-year civil war and the Lebanese are not willing to repeat its woes. Saudi Arabia's Tadawul index is down by about 0.5% since the end of last week.
"I think the prime minister probably caved in to the demands of the Saudis and he declared his resignation from Saudi Arabia".
Many have claimed that the Saudi authorities keep Hariri under house arrest, but members of his party denied those rumors. Responding to Hariri's move, Hezbollah chief Hassan Nasrallah told the nation that Saudi Arabia forced Hariri to step down.
Saudi Arabia accused Iran of an "act of war" after a missile was intercepted over capital city Riyadh.