British Defence Secretary Michael Fallon held talks with Iraqi Prime Minister Haidar al-Abadi on the fight against the Islamic State group Wednesday during an unannounced visit to Baghdad, Abadi's office said.
Britain is carrying out air strikes against the jihadists, who have seized swathes of Iraq, as part of a US-led campaign to help Baghdad's forces push the group back.
During the meeting, Abadi emphasised efforts to increase the "participation of the tribes and their cooperation with our armed forces," the statement from his office said.
The support of the country's powerful tribes will be key in the fight against IS in the Sunni Arab heartland north and west of Baghdad.
But such efforts may have been dealt a blow by the jihadists' campaign of executions against one tribe that opposed it, in which scores have been killed.
Fallon, whose visit had been kept under wraps for security reasons, met Iraq's new Defence Minister Khaled al-Obaidi on Tuesday, the ministry said.
It came as The Times newspaper reported that Britain was preparing to send troops to Iraq to help train local forces to fight IS militants.
The defence ministry in London made no immediate comment on the report but said an announcement would be forthcoming.
Last month, the British defence ministry announced that a team of soldiers was training Kurdish peshmerga fighters to use heavy machineguns supplied by Britain.
Prime Minister David Cameron has ruled out sending combat troops back into Iraq, wary of committing to a new conflict six months from a general election.
The last British forces left Iraq in 2011, eight years after the US-led invasion that overthrew dictator Saddam Hussein.