The U.S. Embassy in Burma has announced the arrival of Washington's first ambassador to the country in 22 years.

The embassy in Rangoon said Ambassador Derek Mitchell arrived Wednesday and would travel to Naypyitaw to present his credentials to President Thein Sein.

Mitchell previously served as special envoy to Burma.

The United States has been re-engaging Burma after a new, nominally civilian government took over in March of last year and began implementing reforms.