The president of Iraq's autonomous Kurdish region, Massud Barzani, held landmark talks in Baghdad on Sunday with Prime Minister Nuri al-Maliki on an array of disputes plaguing relations between the two sides.

Barzani met Maliki, after which the two held a joint news conference in the capital's heavily-fortified Green Zone -- a major change from last year, when the Kurdish leader was advocating the premier's removal from office.

The improvement in relations between the Kurds and the federal government is a rare bright spot for Iraq, which has been hit by a wave of violence that has killed more than 2,400 people this year, and long-running protests by Sunni Arabs who accuse the Shiite-led government of marginalising their community.

"We discussed disputes and we agreed to work on passing frozen laws in the parliament, especially the oil and gas law," Maliki said, referring to long-stalled legislation governing the exploitation of Iraq's rich energy resources.

Barzani said his aim was to send a message that "we are brothers and we are keen to communicate and collaborate."

"We agreed to cooperate and work together and to face everything that threatens Iraq and the (Kurdish) region, and we consider this a national duty," he added.

Barzani admitted that there are "problems and different opinions between the (Kurdish) region and the federal government" in Baghdad.

But "today there is real political willingness to solve the problems," he said.

Kurdish leaders want to incorporate a swathe of land stretching from Iraq's eastern border with Iran to its western frontier with Syria into their autonomous region over the objections of Maliki's government.

The federal and regional governments also disagree over the apportioning of oil revenues. Baghdad has also been displeased with the Kurdish region for signing contracts with foreign energy firms without its approval.

Diplomats and officials say the dispute over territory is one of the main long-term threats to Iraq's stability.

The at-times lighthearted atmosphere of the news conference contrasted sharply with tensions that have marked the relationship between Barzani and Maliki.

Last year, Barzani was a leading critic of the premier, advocated his removal from office and said that Maliki could not be trusted with F-16 warplanes that are on order from the United States.

Later in 2012, the establishment of the Tigris Operations Command, a federal military command covering disputed territory in the north, drew an angry response from Kurdish leaders.

And a deadly firefight during an attempt by Iraqi forces to arrest a Kurdish man in a disputed town pushed tensions higher, with both sides deploying military reinforcements.

But more recently, the two sides have moved to patch up their differences.

Kurdish ministers and MPs ended a boycott of the cabinet and the parliament in May, which was begun in March over objections that the new federal budget did not allocate enough money to pay foreign oil companies working in the region.

And in June, Maliki chaired a cabinet session in Arbil, the capital of the autonomous Kurdistan region, and the two sides agreed to form joint committees to deal with disputes.

Kurdistan's deputy prime minister Emad Ahmed said in a statement on the region's official website that Barzani's visit was a follow-up to Maliki's trip to Arbil.

The US embassy in Baghdad hailed the latest developments in a statement that urged "all of Iraq's leaders to maintain a spirit of national reconciliation and unity" -- something often in short supply in the country's factious politics.

The United States led the 2003 invasion of Iraq and played a major role in shaping the country after dictator Saddam Hussein's fall, but has seen its influence wane since its troops departed at the end of 2011.

UN envoy Martin Kobler also praised the Barzani-Maliki meeting, saying it "confirms that there is political will to address outstanding issues between the centre and the region through direct dialogue and in accordance with the constitution."