American Secretary of State John Kerry (right) meets with Iraqi Prime Minister Nuri al-Maliki in Baghdad, Iraq, on Sunday.

Baghdad - American Secretary of State John Kerry made an unannounced visit to Iraq on Sunday and said he told Prime Minister Nuri al-Maliki of his concern about Iranian flights over Iraq carrying arms to Syria.

Kerry also urged Iraq's Sunni Muslim, Shi'a and ethnic Kurdish factions to commit to the political process as the country's precarious intercommunal balance comes under growing strain from the conflict in neighbouring Syria.

A US official said earlier on condition of anonymity that Washington believes flights and overland transfers from Iran to Syria via Iraq take place nearly every day, helping President Bashar al-Assad crush a two-year-old revolt against his rule.

Kerry said he had told Maliki the Iranian flights through Iraqi airspace were “problematic”.

“Anything that supports President Assad is problematic,” Kerry told reporters. “I made it very clear to the prime minister that the overflights from Iran... are in fact helping to sustain President Assad and his regime.”

Speaking before the meeting, the US official said the Iraqi government had inspected only two flights since last July and that Kerry would argue Iraq did not deserve a role in talks about neighbouring Syria's future unless it tried to stop the suspected arms flow.

Iraqi officials denied allowing weapons to be flown from Iran to Syria through Iraqi airspace. Abbas al-Bayati, a member of the Security and Defence committee in parliament, said: “We have done our duty by randomly inspecting a number of Iranian flights and we did not find any leaked or smuggled weapons.”

“If the US is keen to push us to do more they have to give us the information that they have relating to this,” he said.

Iraq's Shi'a-led government says it takes no sides in Syria's conflict, but its interests are closely aligned with those of neighbouring Shi'a Iran.

According to reporters at a picture-taking session at the start of Kerry's talks with Maliki, the US diplomat appeared to joke that Hillary Clinton, his predecessor, had said Iraq would do whatever Washington asked.

“The Secretary told me that you're going to do everything that I say,” Kerry said, according to the reporters.

“We won't do it,” Maliki, also joking, replied, the reporters said.

More than a decade after the US-led invasion that toppled Saddam Hussein, Sunni Islamist militants linked to al-Qaeda are regaining ground and the country's power-sharing government is all but paralysed.

Thousands of Sunni protesters have taken to the streets since December in protest against Maliki, and Kurdish lawmakers are weighing their options after the Iraqi parliament passed the country's 2013 budget without their participation.

“When consensus is not possible, those who are dissatisfied should not just walk away from the system, should not just withdraw, just as those who prevail should not ignore or deny the point of view of other people,” Kerry said.

Kerry held talks with representatives of all three communities, including Osama al-Nujaifi, the Sunni speaker of parliament.

He also spoke by telephone to Massoud Barzani, president of Iraq's Kurdistan region, which is defying the central government in pressing ahead with plans to build an oil pipeline to Turkey that Washington fears could lead to the break-up of the country.

Sunni protesters accuse the Shi'a-led government of marginalising their minority sect and using anti-terrorism laws to target them.

During his talks with Maliki, Kerry also asked the Iraqi prime minister and his cabinet to reconsider a decision to postpone local elections in two Sunni-majority provinces, Anbar and Nineveh, the US official said.

The Iraqi cabinet last week postponed the votes, which were due on April 20, for up to six months because of threats to electoral workers and violence there - a step Washington believes will only increase tensions.

While violence has fallen from the height of the sectarian slaughter that killed tens of thousands in 2006-2007, Sunni Islamist insurgents have been invigorated by the increasingly sectarian civil war next door in Syria.

More than a dozen car bombs and suicide blasts tore through Shi'a Muslim districts in the Iraqi capital Baghdad and other areas on Tuesday, killing nearly 60 people on the 10th anniversary of the US-led invasion that ousted Saddam.

A statement released by Maliki's office following the talks said they had agreed on the need to find a political solution to the situation in Syria.

“The two sides also expressed concern at the development of events there (in Syria) and the urgency of working to contain it.”

Separately, Kerry said US President Barack Obama had described recent talks with Israeli and Palestinian officials as the most positive he had had to date, but that it would be “foolhardy” to express optimism considering that no negotiations are taking place. - Reuters