Japanese PM Shinzo Abe is in Burma on the first visit by a Japanese head of government since 1977.
A business delegation is accompaningy Mr Abe, who is keen to strengthen economic ties with Burma.
Japan is a key aid donor to Burma, and maintained trade relations with the country during its years of rule by military junta.
Mr Abe is expected to announce $980m (£648m) in development aid during his visit, reports say.
Mr Abe will also meet Burmese opposition leader Aung San Suu Kyi, who he met in Japan last month, AFP news agency reported.
"We will seek to further enhance Japan-Myanmar relations, which have been kept sound for a long time through [Tokyo's] support to [the country's] reforms," Japan's Chief Cabinet Secretary Yoshihide Suga said on Wednesday, using Burma's official name.
In 2012, Japan's previous government agreed to write off more than $3.7bn (£2.29bn) of debt owed by Burma, an agreement honoured by the existing government.
Mr Abe is thought to be keen to help Japanese companies secure infrastructure projects in Burma.
The country has undergone several reforms since a nominally civilian government was installed in 2011.
Hundreds of political prisoners have been released, and censorship rules have been relaxed.
The EU and US have lifted the majority of sanctions against Burma as a result.
However, Burma has experienced serious anti-Muslim violence in recent months.
At least 40 people were killed in violence in central Burma last month, while widespread unrest in 2012 between Buddhists and Muslims in Rakhine state left nearly 200 people dead, and tens of thousands of Rohingya Muslims displaced.