British Prime Minister David Cameron has become the first Western leader to visit Myanmar in decades.
Mr Cameron held talks with President Thein Sein on Friday and will meet pro-democracy campaigner Aung San Suu Kyi.
Speaking on the tarmac as he arrived in the capital, Mr Cameron said the Myanmar government had to demonstrate that moves to democracy were "irreversible".
This trip marks the final leg of Mr Cameron's tour of South East Asia promoting UK interests, the BBC reports.
Myanmar was ruled for almost 50 years by a military junta that stifled almost all dissent and wielded absolute power. The European Union, United States and other nations imposed sanctions. The first general election in 20 years was held in 2010.
The installation of a military-backed, nominally civilian government in March 2011 and a series of reforms since - including the release of hundreds of political prisoners - has led to speculation that decades of international isolation could be coming to an end.
Mr Cameron described Ms Suu Kyi as "a shining example for people who yearn for freedom, for democracy, for progress".
He is the first serving British Prime Minister to visit Myanmar since it gained independence from Britain in 1948.
EU to discuss sanctions
European Union foreign ministers are to discuss policy towards Myanmar on 23 April.
Sanctions, which include an arms embargo, and an assets freeze imposed on nearly 500 people, are due to expire on 30 April.
Earlier this year, the EU lifted travel bans on more than 80 senior officials, including the president.
If they are satisfied that recent steps taken by the government are likely to be sustained, they could ease certain financial sanctions.