Saudi Arabia's King Abdullah has announced that women will be able to vote and run for elections planned for 2015.

In a speech opening a new term of the Shura Council, Abdullah said, "Starting with the next term, women will have the right to run in municipal elections and to choose candidates, according to Islamic principles."

Human rights groups have welcomed the move, but aired frustration over the waiting period of four years.

The king's announcement, once implemented, will change the history of the conservative kingdom that applies a strict version of Sunni Islam, banning women from driving or travelling without the consent of a male guardian.

Human Rights Watch says the reforms are significant, but such promises have been made before, and now women still have to wait four years for the announced reforms to take effect.

"It's the promise we've heard before. When the first municipal elections were held in Saudi Arabia in 2005 at the time, the reason given for excluding women from voting was that they didn't have identification cards," spokeswoman Sarah-Leah Whitson said.

"Here we are over six years later and women are still not voting.

"Instead what we have is a promise that they'll vote four years from now in the next election. So hopefully this is a real promise but at the same time, it is extremely disappointing that women are still being excluded from the elections underway now."

Over 5,000 men will compete in the council's elections, which is only the second in Saudi Arabia's history. Only 285 seats or half of the council are open for elections. The rest is for government appointees.