A council statement on Monday also urged Lebanon to conduct free and fair presidential elections without outside interference, and called on Syria to take measures to stem the flow of arms and people across its border into neighbouring Lebanon.
Syria last year withdrew its troops from Lebanon, after years of politically dominating it, as required by the council's Resolution 1559, adopted in September 2004.
But Lebanon has not yet ordered the Hizb Allah group to disarm, as the resolution also required, even after the group - backed by Syria and Iran - joined the Lebanese government upon winning seats in parliament in 2005 elections.
And arms are still flowing to militias in Lebanon from Syria, Kofi Annan, the UN Secretary-General said last October.
Lebanon has also not yet set new presidential elections to choose a successor to Emile Lahoud, its pro-Syrian president, who secured another three years in office beginning in November 2004 when the parliament, under pressure from Syria, amended the Lebanese Constitution to extend his term.
Terje Roed-Larsen, the veteran UN Middle East envoy told reporters the council statement showed there was "a complete consensus in the council" in favour of implementation of the terms of the 2004 resolution.
He also said it was time for Hizb Allah to revisit its refusal to disarm. But he declined to answer when asked if Lahoud was serving illegally as president. "I am not a lawyer," he said.
John Bolton, the US Ambassador said he saw the statement in terms of Syrian rather than Lebanese obligations, calling it "a clear unanimous signal from the Security Council on what Syria still has to do" to comply with Resolution 1559, including disarming militias operating on Lebanese soil and allowing free and fair Lebanese elections without Syrian interference.
While the statement set no deadline for Lebanese or Syrian actions, "I am waiting for the sound of Syrian compliance", Bolton said.
Fayssal Mekdad, the Syrian ambassador denied his government played any role in the flow of arms across the Syrian-Lebanese border but said Syria was otherwise in the process of complying with all council demands as set out in Resolution 1559.