Myanmar has approved the appointment of the first US ambassador to the former pariah state in 22 years, state media reported on Friday, according to dpa. Derek Mitchell, 47, is an expert on Asian affairs, and has been US President Barack Obama's special representative and policy coordinator for Myanmar since 2011. His appointment marks a significant upgrading of US-Myanmar diplomatic relations, which have been on the mend since US State Secretary Hillary Rodham Clinton visited the country in late 2011. Myanmar held its first general election in two decades on November 7, 2010, bringing to power a government led by the pro-military Union solidarity and Development Party. President Thein Sein has initiated a host of political and economic reforms, including a dialogue with opposition leader Aung San Suu Kyi that paved the way for her to enter mainstream politics. Suu Kyi was to take up her position in parliament on Monday after she and 42 members of her National League for Democracy party won seats in a by-election on April 1. Both the United States and the European Union eased economic sanctions on Myanmar shortly after the by-election. They had imposed the sanctions after the Myanmar army cracked down on a pro-democracy movement in 1988, leaving an estimated 3,000 people dead. The US downgraded its diplomatic presence in Yangon to charge d'affaires level in 1990.