The LNA has not yet responded to the UN’s call for a ceasefire.
According to a statement put out by the GNA in Tripoli, the temporary halt in fighting would include ground battles as well as air attacks.
The UN mission in Libya (UNSMIL) will be responsible for monitoring any violations, the GNA said.
The fighting between the government and Haftar’s troops began in April when they launched a surprise attack on the capital, Tripoli.
Haftar supporters say they are trying to free Tripoli from militias that they blame for destabilising Libya since the fall of Muammar Gaddafi in a NATO-backed uprising in 2011. Haftar had participated in the revolt against Gaddafi.
So far, the LNA has only been able to conquer some suburbs in the south of the city.
Haftar’s critics accuse him of trying to seize power through force and deepening conflict between factions based in the east and west of the sprawling North African country.
His offensive has upended UN-led plans to stabilise Libya after years of conflict that have left the oil-rich nation divided and caused living standards to plummet.
The battle for Tripoli has killed hundreds of people, including combatants and civilians, according to the World Health Organization.
Western powers have become increasingly concerned about the conflict as it risks disrupting oil production and prompting more migrants to leave for Italy and other parts of Europe by boat.