Chinese Foreign Minister Wang Yi held talks in Baghdad on Sunday on issues ranging from trade to arming Iraq's hard-pressed security forces, on the first such visit in over a decade.
Wang met with Prime Minister Nuri al-Maliki, during which the Iraqi premier called for "cooperation in the field of fighting terrorism," a statement from his office said.
Iraqi Foreign Minister Hoshyar Zebari meanwhile hailed China as "the biggest trade partner for Iraq, and the biggest investor in the oil and electricity sectors," during a joint news conference with Wang.
Chinese companies PetroChina and CNPC have substantial investments in Iraqi oil production, which accounts for the lion's share of government revenue.
Baghdad is seeking to dramatically ramp up its oil sales to fund reconstruction of its battered infrastructure.
Zebari also said Wang's visit included discussions on arming Iraqi security forces, which are struggling to curb a year-long surge in violence that has killed thousands of people.
The situation in Syria, Iraq's civil war-torn neighbour to the west, and Iran to its east, which is negotiating with world powers including China on its controversial nuclear programme, were also discussed.
It was "the first visit to Baghdad by a high-ranking Chinese official since 2003", the Iraqi foreign ministry said in a statement on its website.
It follows a trip by Russian Foreign Minister Sergei Lavrov for talks that also included Syria and weapons purchases.
The issue of American weapons deliveries provides an opening in Iraq for other countries to make gains in diplomatic and military ties, a situation Baghdad could also seek to use as leverage with Washington.
Iraqi officials have been angered by delays in the delivery of some US weapons over concerns about potential abuses, and has sought to bolster its forces with purchases made from other sources.