US President Barack Obama sits next to Myanmar's President Thein Sein (L) in the Oval Office at the White House in Washington May 20, 2013. [Photo/Agencies]

WASHINGTON - US President Barack Obama on Monday lauded Myanmar's efforts made over the past two years in holding elections and in solving the country's longstanding ethnic conflicts.

Obama made the statement at a press conference following his talks with visiting Myanmar President Thein Sein at his Oval Office. Thein Sein was the first president of Myanmar to visit the White House in 47 years.

Obama said "Obviously, during this period in between, there have been significant bilateral tensions between our countries".

"But what has allowed this shift in relations is the leadership that President Sein has shown in moving Myanmar down a path of both political and economic reform," Obama added.

But he also stressed "as President Sein is the first to admit, this is a long journey and there is still much work to be done".

For his part, Thein Sein thanked Obama for his administration's policy of re-engagement with Myanmar, which he said has contributed to improved relations between their countries in a short period of time.

Speaking of some successes made by Myanmar, Thein Sein acknowledged that his country has been encountering obstacles and challenges such as poverty, unemployment and the limited size of the middle class.

At the invitation of Obama, Thein Sein started his US tour on May 17, which is a return visit to that to Myanmar made by Obama in November last year.

Washington has, among others, restored diplomatic relations with Myanmar, eased a visa ban and ended sanctions on investment in the country in response to the advances made in the country's reform efforts initiated by Thein Sein after he took office in March 2011.

The Obama administration announced last month that it was mulling a duty-free access for some Myanmar goods to US markets.

According to Myanmar official statistics, the US investments in Myanmar amounted to $243.56 million as of March 2013, with bilateral trade reaching $190.96 million in 2012.