Najib Mikati, a pro-Syrian, chosen with opposition support. BEIRUT, Lebanon (CNN) — Pro-Syrian Lebanese President Emile Lahoud has named former government minister Najib Mikati as prime minister-designate.Mikati, also pro-Syrian, has garnered the support of the anti-Syrian Lebanese opposition by vowing to fire the nation’s security chiefs in the wake of former Prime Minister Rafik Hariri’s assassination.He promised to act in a fair and transparent manner during the process of forming a new government and called the opposition’s backing of him a “wise decision.” “We should take advantage of this opportune moment and deal seriously our difficult times,” Mikati told reporters shortly after his appointment was made public.

It comes two days after Omar Karami, also pro-Syrian, turned in his resignation as prime minister when he failed to form a new government.

Lebanon has been in a political crisis since February, when Hariri was killed in a car bombing. It prompted large-scale demonstrations calling for Syria to leave the country.

Hariri was a key mover in getting a U.N. resolution to call on Syria to remove its troops and intelligence assets from Lebanon. Resolution 1559, passed last year, also calls on Lebanon to disband guerrilla groups.

Now Hariri’s death is at the center of an international investigation authorized by the U.N. Security Council.

A U.N. report released last month said the government of Syria “interfered” with governance in Lebanon in a heavy-handed way that was “the primary reason for the political polarization that ensued” before Hariri’s death.

“It is obvious that this atmosphere provided the backdrop for the assassination of Mr. Hariri,” the report said.

The Lebanese opposition has gone further, saying his assassination was an act of political retribution by Syria.

Syria’s government has said it had nothing to gain and everything to lose in Hariri’s death.

Yet faced with increasing international pressure, the country has agreed to withdraw its forces from Lebanon by April 30, ahead of parliamentary elections in May.

Syria began pulling its 14,000 troops to the Bekaa Valley near the border March 8.

Syria has had a presence in Lebanon since the end of the latter’s 15-year civil war, which mostly pitted Lebanon’s ruling conservative Christians against leftist Muslims, with Syria, Israel and Western international forces — including U.S. Marines — occasionally taking part.

The treaty that ended the fighting revised the constitution to give the Muslim majority a greater role. The presidency, chosen by parliament, goes to a Christian. The prime minister must be a Sunni Muslim.

Mikati said he will meet Saturday with Karami and with government candidates about forming a new Cabinet.

“I have no slogans right now and no description for what the government will look like. This is not a prepackaged government. Negotiations and talks are necessary to choose a government,” he said.

Mikati served as minister of Public Works and Transport, mostly during Hariri’s tenure.