Sudanese FM Mustafa Osman Ismail.

The United States issued an order in 2004 to restrict free movements of Sudanese diplomats in Washington and New York and of those who visited the two cities.

The restriction was slapped as Washington accused the Sudanese government of turning a blind eye to the humanitarian situations in its western Darfur region, where a two-year conflict killed thousands and displaced over one million.

In retaliation, Sudan made a similar decision early March, which requires US diplomats to obtain prior authorization to move beyond 25 kilometers from the presidential palace in central Khartoum.

A Sudanese security official blamed the US embassy in Khartoum for conducting hostile activities against the country.