An eight-member WHO team flew into the region's main city of Arbil and was set to meet, later on Sunday, with Jamal Abdul Hameed, health minister in its autonomous administration.
Another two-member team of WHO veterinarians arrived in Baghdad on Saturday and will head to Arbil on Monday to assist their colleagues from the other team.
"At the moment this is an agricultural emergency," said Sam Yingst, a member of the team in Baghdad.
"But we believe that there is a possibility that it may become a human public emergency though it will require a significant change in the nature of the virus."
A massive cull of poultry has been underway in the northern Kurdistan region after an outbreak of the H5N1 strain of the avian influenza virus among birds.
The disease, which struck after hitting neighbouring Turkey last month, has claimed at least one human life in Iraq and a handful of other cases are under investigation.
Iraq confirmed that a 15-year-old girl in Kurdistan had died from the H5N1 virus in January.
Iraq confirmed the girl had indeed
died of H5N1 virus
Initial reports from a WHO laboratory in Amman said that test results for the virus were negative, but Iraqi authorities later said that the girl was a bird flu victim.
Tests are still under way in Britain on virus samples from the girl's uncle, who also died of a pulmonary infection, and from a woman who hails from the same region and is currently in hospital.
Yingst said the tests on the second individual, which are currently underway in Britain, would be the key.
"We will come to know from the tests of the second person whether or not the virus has shifted or drifted, but at the moment there is no indication of that because, had it occurred, there would have been more cases," he told reporters.
"And if at all it has happened, then this possibility has been elevated by a very significant notch."
No hunting of birds
Jon C. Bowersox, health attache at the US embassy, said that the health minister had also called on residents of other parts of Iraq not to hunt birds.
"Birds that are migrating down from the north could be infected and some people make their income by hunting birds. It is not simply a matter of chicken"
Jon C. Bowersox, health attache at the US embassy
"Birds that are migrating down from the north could be infected and some people make their income by hunting birds. It is not simply a matter of chicken," Bowersox said.
Authorities in Iraqi Kurdistan have quarantined 14 people suspected of suffering from bird flu.
Turkey, which has had 21 cases of the flu strain, was previously the only country outside Asia to report fatalities from the virus. Four people have died there.
The first known cases of H5N1 in humans were recorded in Hong Kong in 1997, when six people died.
Since the virus resurfaced in Asia in 2003 there have been 160 confirmed cases, 86 of them fatal.
The WHO said last week it was also sending thousands of doses of the anti-influenza drug Tamiflu to help control the deadly disease.