John Kerry in Iraq
U.S. Secretary of State John Kerry leaves a meeting with Iraq's Prime Minister Nouri al-Maliki in Baghdad, March 24, 2013. Reuters/Jason Reed

U.S. Secretary of State John Kerry, who accompanied U.S. President Barack Obama on his trip to Israel and Jordan last week, made an unexpected stop in Iraq on Sunday to meet with Iraqi Prime Minister Nouri al-Maliki. The topic at hand: Syria, as usual. In particular, it was the fact that Iraq has been allowing Iran to use its airspace to shuttle weapons to the embattled government in Syria that had the U.S. secretary concerned.

It's no secret that Iran has been providing military support of all kinds to Syrian President Bashar al-Assad in his efforts to keep his crown at all costs. This means Iraq has been allowing the Iranian government to fly arms, and possibly men, through its airspace on its way to Syria. Reuters reported that the Iraqi government has only inspected two flights since last July. Meanwhile, U.S. officials estimate that at least one flight with Iranian weapons on its way to Syria passes through Iraqi airspace every day.

If the U.S. can't convince the Iraqis to ban all incoming Iranian flights, the Guardian reported, then they might settle for better inspection policies.

The Iraqi government officially denies these allegations, and Abbas al-Bayati, a member of the Security and Defense parliamentary committee, told Reuters that Iraq is doing its due diligence by the suspected Iranian flights.

"We have done our duty by randomly inspecting a number of Iranian flights and we did not find any leaked or smuggled weapons," al-Bayati said. "If the U.S. is keen to push us to do more, they have to give us the information that they have relating to this."

Iran has had no air force since the U.S. withdrawal in 2011, the New York Times said.

Kerry plans to speak with the leaders of all three branches of Iraq's coalition government -- al-Maliki, the Shiite Muslim prime minister; Osama al-Nujaifi, the Sunni Muslim speaker of parliament; and Massoud Barzani, president of Iraq's Kurdish region.

Iraq is scheduled to hold elections next month. The last U.S. official to visit Iraq was Hillary Clinton in 2009.