Aung San Suu Kyi has been unanimously re-elected as leader at a landmark congress of the opposition National League for Democracy (NLD) in Yangon.

Hundreds of opposition members gathered on Sunday for the party's first national conference in a meeting that stopped short of making sweeping changes in its ageing top ranks ahead of key elections in 2015.

The gathering was a display of political strength that would have been unthinkable under the military government that ruled the country for decades.

The meeting highlighted the myriad challenges facing the opposition, including its lack of experience as well as internal divisions which saw four members banned from attending, accused of trying to influence the voting.

The NLD had faced calls to inject new blood into its top ranks, dominated by senior members including some in their 80s and 90s, as it eyes key elections due to be held in two years.

But the party held back from a substantial revamp of its leadership, instead selecting older veteran party members to a core executive of 15 and unanimously reappointing Suu Kyi as chairwoman.

"Most of the big decisions are made by that central executive committee and those who were calling for some younger faces, some younger people, to go into that committee will be disappointed," said Al Jazeera's Wayne Hay, reporting from Yangon.

Sweeping reforms

Suu Kyi, a former political prisoner who entered parliament last year, urged the party to "to seize the chance", as it gears up for what is expected to be a major victory if the next election is free and fair.

"I thank the members who struggled hand-in-hand with the NLD for 25 years, and I also welcome our new members," she said. "A party can be energetic if it's refreshed with new blood all the time."

After being sidelined by Myanmar's military rulers for two decades, the party entered the political mainstream last year as a result of sweeping reforms initiated by a new reformist government.

Although hugely popular in Myanmar, some experts question whether the NLD is ready to run an impoverished nation whose economy, education and health systems were left in tatters by the corrupt former military government.

"They could not take power over the country tomorrow. They are not ready. They have a lack of capacity," said a Western diplomat who did not want to be named.

Faultlines have also been detected between the older top party officials - known as the "NLD uncles" - and a younger generation eager to help steer the party as Myanmar enters a new era.

The NLD faces the financial and political might of President Thein Sein's Union Solidarity and Development Party, created by former generals who shed their uniforms to run for office in controversial elections held in 2010.