"The order would be implemented from 6am local time (0300 GMT) on Tuesday," it said.
At least 62 people are reported to have been killed and nearly 200 injured in clashes across the country since violence erupted on May 7 between supporters of the government and the opposition, which is led by Shia organisation Hezbollah.
Saudi Arabia has said that Iran's relations with the Arab world will be affected if Tehran is found to have a role in the opposition's direct action against the government.
"Iran's relations with all Arab countries - if not all Islamic [countries] - would be affected if Iran was supporting the coup that took place in Lebanon," Prince Saud al-Faisal, Saudi foreign minister, said on Tuesday.
Saudi Arabia is a supporter of the Lebanese government.
George Bush, the US president, has said that he will hold discussions with members of the the Lebanese majority bloc to find ways to bolster the faltering government.
"I strongly condemn Hezbollah's recent efforts, and those of their foreign sponsors in Tehran and Damascus, to use violence and intimidation to bend the government and people of Lebanon to their will," he said in a statement.
An uneasy calm prevailed in Beirut on Monday where the road to the international airport was shut for the sixth straight day and a border crossing into Syria was also blocked.
The Saudi ambassador to Lebanon and his family were among 200 people who managed to reach the nearby island of Cyprus by boat, officials there said.
Pressure has been mounting on Lebanese leaders to bring an end to the fighting.
The Hezbollah-led opposition has said it will not tolerate any attempts to be disarmed, insisting it has every right to defend itself.
Hezbollah on Monday welcomed an Arab League decision to send a peace mission, but insisted the delegation must be neutral.
"We ask the Arabs not to favour one party over another," Hussein Khalil, Hezbollah's deputy chief, said.
Michel Aoun, a Christian opposition leader allied with Hezbollah, blamed the government for the "explosion" of violence.
"You should ask those whose decision it was to deploy armed men against the demonstrators whose fault this is," he said.
"The government is to blame. They knew this would instigate an explosion."
Fighting first broke out last week after the Lebanese government - which is boycotted by the opposition - ordered the closure of a private phone network owned by Hezbollah.
The government also suspended Beirut airport's head of security over alleged ties to Hezbollah.
After opposition forces took control of west Beirut on Friday, the army said it would not implement the government's decisions for fear that it could inflame sectarian tensions.
The cabinet of Fouad Siniora, the Lebanese prime minister, is divided over whether to revoke its orders against Hezbollah's communications network.
Samir Geagea, leader of the Lebanese Forces party and a senior pro-government politician, struck a defiant note in a speech on Monday.
"We will persevere," he said. "Hezbollah has made no political gains.
"They will not make the government resign, they will not revoke cabinet decisions until [normality] is restored."
For 18 months the Siniora government has resisted opposition demands to increase its share of posts in the cabinet to give it veto rights, although Hezbollah has now shown it has the military muscle to veto decisions it dislikes.
Arab League mission
Lebanese officials said they expected a Qatari-led Arab mission, formed at an emergency meeting of Arab foreign ministers in Cairo on Sunday, to arrive in Beirut on Wednesday.
|Opposition fighters took control of the Druze|
stronghold of Mount Lebanon on Sunday [AFP]
The mediators will try to quell the violence and tackle the political crisis by securing the election of General Michel Suleiman, commander of the army, as president.
Both sides of the Lebanese political divide had agreed on Suleiman as president, but could not strike a deal over a new government and a law for next year's parliamentary election.
Lebanon's parliament on Monday postponed a vote on a new president for the 19th time, delaying the session to June 10 from Tuesday.
Al Jazeera's Sherine Tadros said: "It seems a deal to end this crisis may be within reach, but it will need the backing of international and regional powers first."
Ban Ki-moon, the UN secretary-general, has condemned those behind the surge of violence and called on all parties to resume talks to find a way out of the crisis.