The head of the UK's armed forces, General Sir David Richards, is visiting Burma to try to build ties with the country's powerful military.
He is the first western military chief to go there since reforms began that have transformed relations with the international community.
Burma's generals, who once ruled the country, have backed reforms so far.
Gen Richards has met his Burmese counterpart, Commander-in-Chief Min Aung Hlaing, and political leaders.
These included President Thein Sein - himself a former general - and opposition leader Aung San Suu Kyi, who has supported the visit.
BBC South East Asia correspondent Jonathan Head said it was unusual for such a senior officer to make a high-profile visit so early in the diplomatic re-engagement with a once isolated country.
But the decision to send Gen Richards to Burma is a reflection of the importance attached by the UK to building relations with the country's military, which remains a powerful but secretive institution, he added.
He went on to say it was not yet clear what kind of relationship Britain and its allies could have with a once vilified military, but this visit has opened channels of communication, which have been closed for many decades.
Currently in Burma, the military holds one quarter of the seats in parliament.
Although the generals have supported the reforms, the army has taken a tough line against ethnic insurgents in Kachin state.
Late last year, they launched a full-scale assault, even as the government was pursuing peace talks.