Myanmar's economy expanded 6.5 percent last year and is set for further modest acceleration, the IMF estimated Wednesday, as sweeping reforms herald hopes of a renaissance for the impoverished nation.

At the end of a mission to the fast-changing nation, the IMF predicted the economy would grow 6.75 percent in the 2013/14 financial year, driven by gas production and investment.

"The authorities' ambitious reform program is bearing fruit, with macroeconomic stability and high investor interest," said the IMF's visit leader Matt Davies in a statement.

He said increasing foreign direct investment was expected to outweigh a widening current account deficit, as the former junta-run country opens to the world.

The comments come as President Thein Sein, a general-turned-civilian, visits the US - the first leader of his country to go there in nearly 50 years as relations are normalized with the world's largest economy.

The US, which has already waived most sanctions on Myanmar in reward for reform, on Tuesday signed an accord to formalize dialogue on trade, a day after Thein Sein made a pitch to US business leaders for investment.

Positive developments include exchange rate and investment law reform as well as "significant increases" in tax collection seen as crucial to pay for higher spending on long-neglected sectors like health and education.