The United States on Thursday welcomed pledges by Morocco's King Mohammed VI to pursue sweeping reforms.

The king announced plans for constitutional reform and real powers for a popularly elected prime minister instead of a royal appointee in a rare national address late Wednesday that comes after protests demanding change.

Washington "welcomes the announcement by King Mohammed VI outlining his pledge to ongoing democratic development through constitutional, judicial and political reforms," the State Department's acting spokesman, Mark Toner said.

"This is a moment of profound change in the region and under the leadership of King Mohamed VI Morocco has made significant achievements in the economic, social and political realms," he stated.

"We fully support the aspirations of the Moroccan people in their efforts to further consolidate the rule of law, raise human rights standards, promote good governance and work toward long-term constitutional reform," Toner added.

"The United States values Morocco as a key strategic partner and we stand ready to work with the government and the people of Morocco to realise their democratic aspirations."