(CNN) -- The party of Myanmar opposition leader Aung San Suu Kyi has requested a change in the wording of the oath that lawmakers have to take, presenting a potential hurdle to her taking up the parliamentary seat she won this month.
The National League for Democracy has asked the authorities to adjust the wording of the oath to say that parliamentarians will "abide by the law" rather than "protect the constitution," Nyan Win, a spokesman for the party, said Wednesday.
Suu Kyi, 66, said in a speech last month that the country's present constitution "does not conform" with democratic norms and should be changed where needed. She also said she would change the configuration of the parliament in which 25% of seats help the military establishment.
Suu Kyi's party won 43 of the 44 seats it contested in by-elections April 1. She is scheduled to attend her first session of parliament Monday after she was elected in the constituency of Kawhmu.
Nyan Win said the National League for Democracy was waiting for Myanmar authorities to respond to the request. He declined to say what Suu Kyi and the other elected members of the party would do if the oath wasn't changed before the parliament session began.
"We believe this problem will be overcome," he said.
News of the complication emerged as Norway announced that Suu Kyi would visit the country in June, her first overseas trip in 24 years. She was released from years of house arrest in 2010.
"We can confirm that she will come here in June, and we are very happy about that," Svein Michelsen, a spokesman for the Norwegian Ministry of Foreign Affairs, said Wednesday.
While in Oslo, Suu Kyi will deliver the Nobel lecture she was unable to give when she was awarded the Nobel Peace Prize in 1991, Nobel spokeswoman Merci Olsson said.
Suu Kyi was under house arrest in 1991 and so could not travel to Norway. Her son, Alexander Aris, delivered an acceptance speech on her behalf.
British Prime Minister David Cameron invited Suu Kyi to visit the United Kingdom in June when he met her last week in Myanmar.
Suu Kyi responded, "Two years ago, I would have said, 'Thank you for the invitation but sorry,' but now I am able to say, 'Well, perhaps' -- and that's great progress."
Cameron reflected that Suu Kyi was allowed to leave Myanmar for some of the past two decades but had not done so because she knew the regime would not let her return.
Myanmar's authoritarian military rulers have begun loosening their grip on power after decades in which dissent was stifled and freedoms severely limited.
In the past 12 months, the government has pardoned hundreds of political prisoners, secured a cease-fire with Karen rebels and agreed to negotiate with other ethnic rebel groups.
U.S. Secretary of State Hillary Clinton described this month's by-elections as "an important step in Burma's democratic transformation."
Western governments have applauded the elections and the other recent reforms by the government of President Thein Sein. The U.S. and Australian governments eased some sanctions on Myanmar this week.
Clinton visited Myanmar in December, a historic trip marking the first time a secretary of state had been to the country in more than 50 years.
And in another sign of improving ties between Myanmar's government and other countries, Thein Sein will visit Japan this week, the Japanese Ministry of Foreign Affairs said Wednesday. Thein Sein will meet with Prime Minister Yoshihiko Noda.
While control of parliament will not change despite the opposition's strong performance in the by-elections, the result nonetheless gives the National League for Democracy a notable presence.
Myanmar's legislature has 664 seats, more than 80% of which are still held by lawmakers aligned with the military-backed ruling party, the Union Solidarity and Development Party.
Suu Kyi led her party to a landslide victory the previous time Myanmar held multiparty elections, in 1990. But the junta ignored the results and placed her under house arrest.
Released in November 2010, Suu Kyi was allowed to crisscross the country to rally support for her party in the elections.
CNN's Per Nyberg and Yoko Wakatsuki contributed to this report.