Baghdad - UN Secretary-General Ban Ki-moon called on Monday for Iraqi leaders to address the "root causes" of a surge in bloodshed as security forces clashed with gunmen in violence-wracked Anbar province.
The UN chief's visit comes just months ahead of general elections, with the country hit by its worst spate of unrest since 2008 and an entire city and parts of another on Baghdad's doorstep in the hands of militants.
It is the first time fighters have exercised such open control in major cities since the insurgency that followed the 2003 US-led invasion, and Ban's remarks echoed US calls for Iraqi officials to focus on political reconciliation, in addition to ongoing military operations.
"I would urge the leaders of the country... to address the root causes of the problems," Ban said during a joint news conference with Prime Minister Nuri al-Maliki.
"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 security situation in Iraq is undoubtedly a source of great concern," the UN chief said, adding that he is "deeply concerned by this escalation of violence in Anbar governorate."
Ban noted that civilian casualties were at the highest level since 2008, and said that "the government and people of Iraq must unite in addressing this terrorism".
He 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, the mostly-Sunni desert province in west Iraq which shares a long border with Syria.
The country is also experiencing its worst prolonged period of violence since 2008, when it was emerging from a bloody Sunni-Shi'ite sectarian war that left tens of thousands dead.