Britain's next prime minister met with Iraqi leaders on Monday in a surprise visit following promises to study his country's participation in the conflict.

Treasury chief Gordon Brown, who is to succeed Tony Blair later this month, arrived Monday for a one-day fact-finding mission, according to the British Embassy.

Iraqi Prime Minister Nouri al-Maliki's office said the two men had begun their meeting, which occurred even as Britain's opposition Conservative Party called on the British Parliament to back a formal inquiry into Blair's decision to go to war in Iraq.

Brown also was due to meet with Iraqi President Jalal Talabani, Finance Minister Bayan Jabr and Lt. Gen. Graeme Lamb, Britain's senior military officer in the region, a spokesman said, speaking anonymously in line with official policy. He refused to give any further detail.

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The visit was not publicly announced in advance of Brown's arrival, which occurred amid tight security. Mortar attacks struck Baghdad and the southern city of Basra during a visit by Blair last month.

Brown has said he understood the war in Iraq was a "divisive and difficult" issue but he stood by the decision to join the U.S.-led invasion in March 2003.

Brown has not outlined what his specific policies on Iraq will be, though he has indicated that he wants to devote more time and resources toward the creation of jobs and basic services.

It was Brown's second visit to Iraq after a trip in November, according to an official at the British Embassy in Baghdad, who also declined to be identified because of official policy.

Blair is to leave Downing Street on June 27, and Brown will take over as both leader of the governing Labour Party and prime minister.

The Conservative Party urged the British Parliament on Monday to back a formal inquiry into the decision to go to war in Iraq.

"We want the principle established that there must be an inquiry. It's about making sure we don't make the same mistakes again," said Liam Fox, the party's defense spokesman in Parliament.

Prime Minister Tony Blair has ruled out an inquiry while British troops are deployed in Iraq.

The government was expected to defeat the motion, but interest would focus on how many members of Blair's Labour Party will back the proposal.

At the time the Conservative Party strongly supported Blair's decision to back the U.S.-led invasion.

Complete coverage is available in FOXNews.com's Iraq center.