UN Secretary General Ban Ki-moon today called for all parties in Lebanon's political crisis to maintain calm and work for a compromise on electing a president.
Lebanese President Emile Lahoud ordered the army to take charge of security on today after political rivalry blocked the election of his successor hours before he was due to step down.
The Lebanese parliament failed on to grasp its last chance to elect a head of state before the pro-Syrian president's term expires at midnight (10pm Irish time).
Mr Ban's spokeswoman said in a statement: "The Secretary General is deeply concerned at the fragility of the situation in Lebanon and is following events very carefully," it added.
The speaker of parliament asked members to meet again next week for another attempt. The country is now in a political vacuum, with rivals claiming to be the legitimate power.
The constitution stipulates that the serving government takes on presidential powers until a new head of state is elected.
Western-backed Prime Minister Fouad Siniora said the cabinet will assume presidential powers until a new president is agreed.
But Mr Lahoud insists the cabinet is illegitimate since Shia ministers resigned from the coalition last year.
After the vote failed to take place, Mr Lahoud said "the dangers of a state of emergency exist and have been fulfilled" but experts said the wording fell short of a declaration of a state of emergency.
Another prominent opponent of the Siniora government, Christian leader and presidential candidate Michel Aoun, said in a statement the existing cabinet would become a "usurper government" as soon as Mr Lahoud leaves office.
Under Lebanon's sectarian power-sharing system a Maronite Chrstian must be president and he ahs proposed an as yet unnamed candidtae who will not come from party.
Unless a consensus candidate emerges soon, the country could end up with competing administrations as at the end of its 1975-1990 civil war.
Despite the claims of rival factions, there was no sign that the conflict would lead to violence soon.