Maoist leaders have returned to Nepal's capital to push forward talks on drafting an interim constitution to share power with political parties ahead of national elections, a rebel spokesman has said.

"Maoist chairman Prachanda and leader Baburam Bhattarai arrived in Kathmandu Saturday evening to engage in consultations regarding the peace process. They will stay in the capital for the next couple of days," Ananta, the central region rebel commander who uses just one name, told AFP.

The two sides agreed on a historic power-sharing in June that saw the rebel leader emerge from hiding after a decade to meet with Prime Minister Girija Prasad Koirala to create a framework to end an insurgency that has claimed more than 12,500 lives.

The eight-point deal includes drafting an interim constitution to allow the rebels to join the government and then elect a constituent assembly to rewrite the 1990 constitution, including a proposal to abolish or severely limit the role of the 250-year-old monarchy.

King Gyanendra, who sacked the government and seized power in February 2005, was forced to hand back control to an alliance of seven political parties in April after weeks of bloody protests.

Since then, the interim government has stripped him of all political authority including his control of the army.

A key sticking point however remains setting up a system of arms management for the army and the rebels, likely monitored by the United Nations, to create a conducive environment for constituent assembly elections.

The rebel leaders met with Madhav Kumar Nepal, general secretary of the Communist Party of Nepal-Unified Marxist Leninist and held discussions on political issues Sunday morning.

"The Maoist leaders discussed the agreement reached with the seven-party government and other political developments," said Yadav Sharma, personal assistant to Nepal.

Discussions between Prachanda and Koirala were expected later this week, Sharma said, following the prime minister's return from Bangkok on Tuesday.

The 84-year-old prime minister had left for Bangkok for medical treatment last week after the deal with the Maoists.

"A meeting of the top leaders of the seven parties will be held immediately after the PM's return. This will be followed by high-level talks between the Maoist chief and the government," said Narayan Man Bijukchhe, chairman of the Nepal Workers and Peasants Party, who also met with Prachanda on Sunday.