Burmese opposition leader Aung San Suu Kyi, on her first visit to Europe in nearly a quarter of a century, warned that her country's political transformation was not irreversible and the military had to give up its excessive powers.

Ms Suu Kyi, in Norway to accept her 1991 Nobel Peace Prize, called for national reconciliation.

"We are not at the end of the road, by no means, we are just starting out," said a tired-looking, rarely smiling Suu Kyi, who still appeared to be recovering from falling ill yesterday.

However, she rejected a suggestion that her aim was to dismantle the military.

"I have never thought that I was doing anything against the military, I've always said I want the military, the army to be an honourable, professional army that is respected by the people," Ms Suu Kyi said at a press conference with Norwegian Prime Minister Jens Stoltenberg tonight.

"I fight against what is dangerous for the democratic process and the military having the kind of powers that they shouldn't have certainly endangers the democratic process," she said.

Ms Suu Kyi, who spent a total of 15 years under house arrest between 1989 and her release in late 2010, has been negotiating a fragile transition with President Thein Sein and entered parliament in a special by-election in April.

An official dinner in Switzerland for Ms Suu Kyi was cancelled last night after she complained of jet-lag and exhaustion.

A spokesman for the Swiss Foreign Ministry said she was simply tired.

Her press conference in the Swiss capital Bern last night ended early after Ms Suu Kyi became sick and left.

After about 15 minutes of taking questions alongside Swiss Foreign Minister Didier Burkhalter, who announced Switzerland was lifting sanctions against her country except for military weapons, she suddenly had a pained look on her face and reached for a bag into which she threw up.

Ms Suu Kyi, wearing a pink silk outfit, regained her composure and left the news conference saying: "I'm so sorry. I apologise."

Ms Suu Kyi, on her first visit to Europe for 24 years, is due to visit Dublin on Monday.

Among her planned engagements will be a meeting with President Michael D Higgins. She will also meet Tánaiste Eamon Gilmore.

She will attend a concert in her honour organised by Amnesty International and receive Amnesty's Ambassador of Conscience Award.