Lebanon's pro-Syrian president, Emile Lahoud, says he will appoint an interim government headed by the army chief if parliament cannot agree on a new head of state before his term expires in November.
Army commander Michel Suleiman has not confirmed if he would accept the job.
Pro- and anti-Syrian political blocs in parliament have been deadlocked over choosing a new president.
Earlier Thursday, a Lebanese lawmaker allied to the Western-backed government announced his candidacy for the presidency.
Boutros Harb, a Maronite Christian, said Thursday that if elected president in a parliamentary vote later this year, he would work to end Lebanon's 10 month political stalemate.
Harb also called for dialogue and reconciliation with Syria to improve tense relations with Lebanon's neighbor.
Parliament traditionally chooses a Maronite Christian as president, as part of a sectarian division of political powers.
But Lebanon's Christian community is sharply divided between those who support the pro-Western government of Prime Minister Fuad Siniora, and followers of pro-Syrian General Michel Aoun, who is allied with the Shi'ite militant group Hezbollah.
Former Prime Minister Aoun also is expected to be a candidate for president.
Lebanon has been in political stalemate since November, when Hezbollah withdrew from the Cabinet of Mr. Siniora, demanding a greater say in decision-making.
The move left Mr. Siniora with a small parliamentary majority and put him at odds with parliament speaker Nabih Berri, a Hezbollah ally.
Some information for this report provided by Reuters and AFP.