The United States on Friday expressed "deep concern" about the deteriorating political situation in Mali, calling on the junta leader to step aside and allow for the return of full civilian rule.

"The CNRD's continued interference in the government has undermined democracy in Mali, led to the de facto partition of the country, and crippled the ability of the country to respond to a developing humanitarian crisis in northern Mali," State Department spokeswoman Victoria Nuland said in a statement.

She urged coup leader Amadou Sanogo and members of the National Committee for the Redressment of Democracy and Restoration of the State (CNRD), which was set up by the junta after the March 22 coup d'etat, to step down.

"We hold the CNRD directly responsible for the increasing suffering of the Malian people," Nuland said. "The military needs to stand aside completely in order to let the interim administration led by President Dioncounda Traore and Prime Minister Cheick Modibo Diarra govern freely and to organize presidential elections as expeditiously as possible."

Traore took office on April 12 for a 40-day mandate under an agreement reached with the junta. However, West African leaders said last month that they wanted him to stay in office for as long as a year to oversee the return of civilian rule, an idea that was rejected by the junta.

The junta has continued to hold sway in the West African nation, and arrested several former government officials linked to ousted President Amadou Toumani Toure.

The Tuareg rebels, who have long claimed northern Mali as their homeland, had seize all the main towns in the desert north by taking advantage of the chaos.

"A strong, stable democratic government in Mali is essential in order for the country to deal successfully with its multiple economic, social and security challenges," Nuland said.

"The U.S. will maintain its targeted sanctions against Captain Sanogo and other CNRD leaders as well as the Malian government until the military stands down and democracy is returned to Mali," she added, referring to the travel ban imposed early last month.