Western governments have praised Myanmar's move toward democracy. Piebalgs, during a news conference, said he was "impressed" with the pace of reforms.
"I took note of the significant progress in negotiating peace settlements with ethnic groups, a key ingredient for stability and prosperity," he said.
In mid-January, a truce was signed between government officials and the rebel Karen National Union in territory near the Thai border.
Piebalgs added he received assurances from Myanmar's leaders that more prisoners of conscious would be considered for release.
"The EU wants to support the momentum for change, in response to progress," he said.
Suu Kyi, a former long-time political prisoner and who was awarded the Nobel Peace Prize in 1991, is to run in the by-elections set for April. Her National League for Democracy won an election in the 1990s but the results weren't recognized by the country's military leaders.