"We are able to protect Tripoli, and we are ready for this, we will drive Haftar's militia back to where they came from," Maiteeq said at a press conference in Rome.
According to Maiteeq, the situation on the ground in Libya has improved significantly two weeks after the beginning of Haftar's offensive.
"The position of the GNA is clear. We are talking about a coup, Haftar must go," he said, calling the LNA's offensive "an invasion" and an "attack on the legitimate government."
Maiteeq also announced GNA's readiness to discuss the introduction of a no-fly zone in Libya.
Meanwhile, the head of Libyan GNA State Council, Khaled Mishri, has accused the Arab League Chief of siding with Haftar.
"We did not see the League of Arab States taking a stance against the fighting. Its [general] secretary has sided with Haftar," Mishri said during a news conference.
He added that the council would participate in an inter-Libyan dialogue only if Haftar would not be part of it.
Libya remains divided between the LNA-backed parliament, which was elected in 2014 and is based in the city of Tobruk, and the GNA, which was formed as part of a UN initiative and controls the western part of the country, including the capital Tripoli.