Trump's announcement last week was a departure from longstanding U.S. policy on Western Sahara, which drew disapproval from some organizations including the UN and the Algeria-backed Polisario Front, a breakaway movement that seeks to establish an independent state in the territory.
Germany has reportedly requested the UN to hold a closed door 15-member Security Council meeting on the situation.
U.S. Ambassador to the United Nations Kelly Craft sent a copy of Trump's proclamation recognizing "that the entire Western Sahara territory is part of the Kingdom of Morocco" to UN chief Antonio Guterres and the Security Council on Tuesday.
The United States had supported a 1991 ceasefire between Morocco and Polisario Front. The ceasefire is monitored by UN peacekeepers.
The region has effectively been split by an earthen wall separating an area controlled by Morocco that it claims as its southern provinces, and territory controlled by the Polisario with a UN-mandated buffer zone between them.
UN talks have long failed to broker an agreement on how to decide on self-determination. Morocco wants an autonomy plan under Moroccan sovereignty. The Polisario wants a UN-backed referendum including on the question of independence.
U.S. President-elect Joe Biden, due to succeed Trump on January 20, will face a decision whether to accept the U.S. deal with Morocco on the Western Sahara, which no other Western country has done. A Biden spokesman declined to comment.
Last Thursday, the United Nations said its position was "unchanged" on the disputed region. "UN Secretary-General Antonio Guterres believes the solution to the question can still be found based on Security Council resolutions," said Stephane Dujarric, the secretary-general's spokesman.
On October 30, the Security Council extended the UN peacekeeping mission, known as MINURSO, for one year, adopting a resolution that emphasizes the need for a realistic, practicable and enduring political solution to the Western Sahara question based on compromise, as well as the importance of orienting United Nations resources to that end.