"France and Spain support our plan because they see it as a solution to satisfy the demands of the population in Western Sahara as well as the demands of the international community," the government official said.
Morocco claims centuries-old rights over the Western Sahara, a territory rich in phosphates, fisheries and possibly offshore oil.
Rabat annexed the region in 1975 when Spain withdrew, triggering a low-level guerrilla war with the Polisario Front, which has its headquarters in Algeria.
A UN ceasefire agreement in 1991 promised a referendum to decide the territory's future, but the vote never took place.
Rabat now says such a referendum is impossible and autonomy is the most it will offer.
Morocco says its plan would ensure all political and human rights for Sahrawis in the territory.
It also believes that stability in the Maghreb region will increase as it would end strained links with Algeria due to the dispute.
Polisario, which seeks the independence of the territory, has rejected any autonomy plan and presented its own plan to the UN on Tuesday.
The group described its proposal as "a flexible and constructive solution which guarantees Sahrawi national rights", but it gave no specific details.