UN Secretary-General Ban Ki-moon has arrived in Burma to see how the world body can help promote the country's tentative steps towards democratic reform.
Mr Ban will meet president Thein Sein and visit a UN drug control project during the three-day visit. He will also pay his respects at the tomb of U Thant, a Burma diplomat who was UN secretary-general in 1961-71.
His visit is the latest in a series by foreign dignitaries since Mr Sein's reform campaign gathered steam by winning the endorsement of the leader of Burma's democracy movement, formerly jailed Aung San Suu Kyi.
Mr Sein came to power a year ago after a general election that left the military in firm control but signalled a desire for political reconciliation. Also currently visiting Burma are German foreign minister Guido Westerwelle and Baroness Ashton, the European Union's foreign policy chief.
Since January, Burma has also hosted the foreign ministers of Britain, France and Canada, as well as British Prime Minister David Cameron. Their visits have heralded the easing of sanctions their governments had maintained against Burma because of the previous military regime's repressive policies.
Western nations had held out the prospect of easing sanctions if Mr Sein, a former general who retains close ties to the military, continues the political liberalisation he began after taking office a year ago.
The European Union last week announced it was suspending for a year, rather than dropping outright, most of its sanctions as a way of sustaining pressure for change. An arms embargo remains in place because of counter-insurgency campaigns Burma's army continues to carry out against rebel ethnic minorities.
Mr Ban last week said he is making his visit because there is "an unprecedented opportunity" to help democratic change in Burma at this "critical moment". He said he would explore practical ways the United Nations can help the country.
The UN chief said Burma has seen encouraging economic and political reforms followed by recent landmark elections and important steps toward reconciliation, but he said the country's transition is also fragile and many challenges lie ahead.
Mr Sein's reforms are seen as being mainly driven by a desire for sanctions to be lifted, with those imposing them gradually easing restrictions in return for more reforms, which so far have included the freeing of many political prisoners and reconciliation with Suu Kyi's pro-democracy movement. Mr Westerwelle said after meeting Suu Kyi that Germany wants to support a "sustainable way for democracy, freedom and the rule of law."