United States Special Envoy Derek Mitchell arrived?in Yangon?Monday in an attempt to further look into Myanmar's most recent development, official sources said.

It is Mitchell's fourth visit to Myanmar.

The US State Department described Mitchell's trip as a follow-up one to that of Secretary of State Hillary Clinton in December last year.

Besides meeting with government officials in Nay Pyi Taw, Mitchell, US special representative and policy coordinator for Myanmar, will also travel to Bagan to see microfinance programs and other development work in the country's dry zone.

Mitchell's visit will last for four days through to Thursday. He last visited Myanmar in November, 2011.

Along with Mitchell, senior US diplomat Luis CdeBaca, who is US Ambassador at Large to Monitor and Combat Trafficking in Persons, will also pay a three-day visit to Myanmar to assess the human trafficking situation in the country and to explore opportunities to strengthen the government's anti-trafficking efforts.

CdeBaca will also discuss with Myanmar officials steps to address transnational sex trafficking and improve labor conditions for workers, according to the US State Department which added that he will also meet with non-governmental organizations, international organizations, and the National Human Rights Commission.

During the three-day official visit, Myanmar President U Thein Sein met with Clinton and the two countries sought grounds for normalization of relations which were stranded for over two decades.