The United States supports Morocco's autonomy plan for the disputed territory of Western Sahara, considering it both credible and realistic, the US mission to the United Nations said on Saturday.
The announcement on Twitter comes amid an escalating spat between Rabat and the United Nations.
Morocco accused UN Secretary-General Ban Ki-moon last week of no longer being neutral in the conflict, criticising his use of the word "occupation" to describe Morocco's annexation of the region at the centre of a struggle since 1975, when it took over from colonial power Spain.
This week Morocco ordered the United Nations to withdraw 84 international civilian personnel from its peacekeeping mission in Western Sahara, MINURSO. It said this was a response to Ban's "unacceptable" remarks.
"We consider Morocco autonomy plan serious, realistic, credible," US mission spokesman Kurtis Cooper said on his Twitter feed. "We continue to support the UN-led process to bring about a peaceful, sustainable, and mutually-agreed solution to conflict in Western Sahara."
He added that the United States continues to support the work of MINURSO in Western Sahara.
The controversy over Ban's comments is Morocco's worst dispute with the United Nations since 1991, when the UN brokered a ceasefire to end a war over the Western Sahara and established the mission.
Earlier this month, Ban visited refugee camps in southern Algeria for the Sahrawi people, who say Western Sahara belongs to them and fought a war against Morocco until the 1991 ceasefire.
Their Polisario Front, a Sahrawi movement aiming to end Moroccan presence in the Western Sahara, wants a referendum, including over the question of independence, but Rabat says it will only grant semi-autonomy.
Ban's spokesman said on Friday that he was disappointed by the UN Security Council's failure to take a strong stand in the dispute between him and Morocco over Western Sahara and would raise it with council members soon.
Diplomats said the council members that argued against a strong statement of support of Ban and in favour of countries dealing with the issue bilaterally included Morocco's traditional ally France along with Spain, Egypt and Senegal. Council statements need to be unanimous.
France has offered to mediate between Ban and Morocco.
The Polisario's UN representative Ahmed Boukhari told reporters on Thursday that Morocco's goal was to shut down MINURSO, which he said "would mean the shortest way to the resumption of war."
Ban has said he wants to restart stalled negotiations between Morocco and Polisario Front.