President Barrack Obama on Thursday nominated a defense official as U.S. special envoy to Myanmar with the tough job of negotiating with its military-dominated government and pushing for reform.

Derek Mitchell will have the rank of a State Department ambassador if confirmed by the Senate in the position, which was mandated in 2008 legislation but has yet to be filled.

Mitchell, a China scholar with wide experience in Asia, is principal deputy assistant secretary of defense for Asian and Pacific security affairs. Early in his career, he worked on the foreign policy staff of Sen. Edward M. Kennedy, D-Mass., and then for a Taiwanese newspaper, China Post. He has also held positions at Washington-based think tanks, including the Center for Strategic and International Studies.

As special representative and policy coordinator for Burma, as Myanmar is also known, Mitchell would be charged with speaking with the government and opposition leaders, coordinating U.S. policy and working with the international community.

In the past 18 months, the Obama administration has shifted the longstanding U.S. policy of isolating Myanmar's generals, attempting to engage them while retaining sanctions imposed because of the military's poor record on human rights and democracy.

The policy has made little headway. Elections staged in November ushered in an overwhelmingly pro-military government, although opposition leader Aung San Suu Kyi was then released from years of house arrest. Her party, whose 1990 election victory was never honored, has been outlawed because it refused to contest the latest polls which it said were unfair.

Myanmar's Southeast Asian neighbors have called for Western nations to lift sanctions. On Tuesday, the European Union eased its restrictions a little, lifting a visa ban on some civilian members of the government.

The U.S. says it is premature to lift sanctions. It is urging Myanmar to release its more than 2,000 political prisoners and open up its politics. Washington is also concerned about Myanmar's alleged nuclear ambitions and trade in weapons with North Korea.