Kigali  - Rwandan President Paul Kagame would be able to run for a third term in 2017 and potentially stay in power until 2034, thanks to a constitutional amendment passed by the country's Senate on Tuesday despite the opposition slamming the move as undemocratic.

"We are happy to vote for the lifting of the presidential term limits as requested by the people," Senate President Bernard Makuza told dpa.

The possibility of changing the constitution had already been approved by the lower house of Parliament and the Supreme Court.

The amendment, which is still to be confirmed by a referendum, cuts the presidential term from seven to five years and maintains the current two-term limit, the weekly Jeune Afrique reported.

But it allows for an exception for Kagame, who could seek another seven-year term and then run for two five-year terms, extending his rule to 2034.

The referendum is widely expected to win a majority of votes. More than 3 million Rwandans had petitioned Parliament to change the constitution.

But opposition leader Frank Habineza said the move had been "pushed by the ruling party and not Rwandans."

Kagame has been a key figure in Rwandan politics since 1994, when rebels led by him put an end to a genocide by Hutu extremists that left an estimated 800 000 Tutsis and moderate Hutus dead.

He won the 2003 presidential election, and was re-elected in 2010.

Neighbouring Burundi has been in turmoil since April, when President Pierre Nkurunziza announced his bid to seek a third term. The violence has continued after Nkurunziza won a July election boycotted by the opposition.