The United States on Wednesday said it would raise with Iraqi Kurdish leaders a controversial decision to delay regional presidential elections by two years in a battle over whether leader Massud Barzani can run again.

The lawmakers agreed on Sunday to delay the presidential polls, but said parliamentary and provincial elections due September 21 will go ahead as planned.

The delay to the presidential polls is the latest step in a months-long battle over whether Barzani, the dominant figure in the autonomous three-province region, can remain in office.

The opposition argues Barzani has served the maximum-allowable two terms in office, but the dominant Kurdistan Democratic Party (KDP) and its smaller partner the Patriotic Union of Kurdistan (PUK) have pushed for a referendum on a new constitution which would, if approved, allow him to serve up to two more.

"We will be engaging with officials there to discuss the implications of this decision," State Department spokeswoman Jen Psaki said.

"The United States supports regular, free and democratic elections as fundamental to ensuring the will of the people."

But she said Washington was hopeful that the stumbling block would be overcome once the new Kurdish parliament is elected.

"We are confident that the new Kurdish regional parliament will take up issues of concern to the Kurdish people, such as finalizing a regional constitution and presidential elections," Psaki said.

"We're hopeful that this will all happen soon and that they will undertake to put in place elections soon."

Barzani's KDP and the PUK, headed by ailing Iraqi President Jalal Talabani, have largely held a duopoly in Kurdish politics and have even run on a joint slate in recent elections.Together, the two parties hold a majority of seats in Kurdistan's 111-seat regional parliament.

Kurdistan is held up as a paradigm of economic growth and stability in an Iraq still beset by deadly violence and chronic political crises, but critics say its two main parties blur the lines between state office and their own party bureaucracies, fostering nepotism and corruption.