Iraqi Prime Minister Nuri al-Maliki was due to meet with members of Congress on Wednesday as he seeks increased military aid to fight sectarian violence amid criticism from US lawmakers that his government has contributed to the divisions.

As he traveled to Washington on Tuesday, six influential US senators took a hard line against Maliki in a letter to President Barack Obama.

"By nearly every indicator, security conditions in Iraq have dramatically worsened over the past two years. Al Qaeda in Iraq has returned with a vengeance," wrote Democrats Carl Levin and Robert Menendez and Republicans John McCain, James Inhofe, Bob Corker and Lindsey Graham.

The letter urged Obama to press Maliki to formulate a strategy to stabilize the country, citing UN estimates that more than 7,000 civilians have been killed in Iraq this year.

"Unfortunately, Prime Minister Maliki's mismanagement of Iraqi politics is contributing to the recent surge of violence," the letter said.

Maliki is urgently seeking military supplies to fight an upsurge in sectarian violence spilling over the Syrian border. He also was expected to present himself to Obama as a potential mediator with Iran and its ally, the Syrian president.

During the visit, Maliki was due to meet with members of Congress including Menendez and Corker, the leaders of the Senate Foreign Relations Committee, and the Republican and Democratic leaders of the House Foreign Affairs Committee. He was due to meet with Obama on Friday.

US officials, particularly in Congress, have watched in dismay as Maliki ignored its calls to build consensus and moved closer to Iran.

Reuters