United Nations General Secretary Ban Ki-moon has urged Myanmar President Thein Sein to continue pushing for democratic reforms, as the leading opposition party agreed to end its boycott of parliament and swear an oath to the constitution.

The U.N. chief is in Myanmar, also known as Burma, on a three-day visit, where he will address parliament in the capital Naypyitaw on Monday -- the first foreign leader to do so -- before meeting with opposition leader and one-time political prisoner Aung San Suu Kyi on Tuesday.

On Wednesday, members of Suu Kyi's National League for Democracy party will travel to the capital to attend a parliamentary session on Wednesday.

We need to support Myanmar so it doesn't slide back down the scale, Ban told reporters on Sunday, according to Reuters. 

He went on to describe Sein as a key driver in the country's bid to reform.

Myanmar, which has been ruled by a repressive military junta for decades, has recently taken steps to allow free elections, freedom of the press and other liberalizing measures, which have gone down well with foreign powers.

Only last week, Canada said it would suspend some of its sanctions against the regime, in the wake of similar actions by other western nations following historic elections earlier this month.

There was a wrinkle to all the benevolent news, however, when opposition party officials refused to abide by an oath to parliament, which they felt was a tip of the hat to the military. Now, Suu Kyi has retracted the boycott. The NLD had previously taken issue with the wording of the constitution, wanting to replace the words safeguard the constitution with respect the constitution in an oath.

As a gesture of respect to the desires of the people and in consideration of the requests made by lawmakers from democratic parties and independent lawmakers, we have decided to attend the parliament, Suu Kyi told reporters after a meeting of party leaders.

We will go there as soon as possible and take the oath and attend the parliament, she added.