Libyan lawmakers have not yet reached agreement on a national unity government that is meant to stitch the oil-rich but chaotic north African country back together, a U.N. envoy said.

Bernardino Leon had said that the United Nations hoped to announce the unity government on Wednesday.

"We hope that tomorrow at the latest to be able to announce this unity government," Leon told reporters at a midnight briefing in Skhirat, Morocco. He said there was "no need to introduce modifications" into what has been described as the final draft of a peace deal.

Libya is split between an Islamist-backed government based in Tripoli and an internationally recognized government in the country's east. The U.N. is trying to broker a deal to unify them and bring peace to a country that fell apart after the overthrow of former dictator Moammar Gadhafi in 2011.

Even as lawmakers were in session Wednesday to debate names for the potential unity government, Libyan security officials said an explosion went off next to the parliament in the capital, Tripoli.

The officials, who are loyal to the Tripoli-based government, said no casualties were reported. The officials spoke on condition of anonymity because they aren't authorized to speak to reporters.

No one immediately claimed responsibility for the explosion.

The internationally recognized government on Monday voted to extend its mandate past the Oct. 20 deadline that was part of a political roadmap sketched out after Gadhafi was overthrown. The move signaled a lack of confidence in the U.N. efforts toward a peace deal.

U.S. Secretary of State John Kerry and U.N. Secretary-General Ban Ki-moon and others at a high-level U.N. meeting on Friday urged Libya's rival governments to act quickly and reach a deal.