Rebels have ended their boycott of Ivory Coast's power-sharing government.
The two sides have started to disarm
An AFP journalist saw five of the eight rebel ministers, accompanied by Prime Minister Seydou Diarra, arrive under heavy security for a cabinet meeting.
Ivory Coast has been divided between the rebel-held north and the government-controlled south since the insurgency began in September 2002.
Rebels pulled out in September, accusing the president of failing to implement a French-brokered peace deal.
The leader of the New Forces rebels and Communications Minister Guillaume Soro is expected to take rejoin the cabinet on Wednesday, AFP reports.
Some 5,000 French and West African troops have been monitoring a fragile ceasefire between the two sides.
In December, the government and rebels began disarming and withdrawing weapons from the ceasefire line.
Elections are planned for 2005.
The rebels accuse Mr Gbagbo of discriminating against Muslims and northerners, many of whom are of foreign origin.
Despite the New Forces' absence, the government has approved a bill aimed at meeting some of their demands.
If passed, the nationality rules for presidential candidates would be watered down, so candidates could run if they have one Ivorian parent, not two as at present.
Opposition leader Alassane Ouattara, a Muslim northerner, was barred from past elections because his parents were from Burkina Faso.
Another bill would make it easier for those of foreign origin to own land.
However, Mr Gbagbo says that these measures would have to be subject to a referendum, while the rebels want them to be passed, like other laws, by parliament.