Iraqi leaders should address the underlying causes of a protracted surge in violence plaguing the country, UN Secretary General Ban Ki-moon said on Monday during a visit to Baghdad.

"I would urge the leaders of the country ... to address the root causes of the problems," Ban said.

"They should ensure that there is nobody left behind. There should be political cohesion" and "social cohesion, and political dialogue, inclusive dialogue," he said.

The UN chief spoke after landing in the Iraqi capital for a two-day visit to the country, where he was also due to meet with parliament speaker Osama al-Nujaifi and other lawmakers, Vice-President Khudayr al-Khuzaie and the head of Iraq's election commission ahead of polls due in April.

Ban's visit comes as Iraq is embroiled in a bloody standoff between government forces and militants and anti-government tribes in Anbar province, the mostly-Sunni desert province in west Iraq which shares a long border with Syria.

The country is also experiencing its wost prolonged period of violence since 2008, when it was emerging from a bloody Sunni-Shiite sectarian war that left tens of thousands dead.