Turkey believes Iraqi Kurds, who voted in large numbers in Sunday's election, are trying to wrest control of Kirkuk at the expense of local Arabs and Turkish-speaking Turkmen.
Ankara fears this could herald a concerted drive to build an independent Kurdish state in northern Iraq, which might in turn reignite separatism among the Kurds of southeastern Turkey.
"Some people are looking the other way while mass migration [of Kurds to Kirkuk] takes place," the Wall Street Journal on Monday quoted Erdogan as saying in an interview given on the sidelines of the World Economic Forum in Davos, Switzerland.
"This is going to create major difficulties in the future," Erdogan said.
He added that US President George Bush had assured him he would look into the matter, but had done nothing so far.
Many Arabs and Turkmens in Kirkuk appeared to boycott Sunday's Iraqi elections in protest at what they saw as voting rules favouring the Kurds.
Erdogan says Turkey is taking its
own precautions over Kirkuk
Erdogan, who gave his interview before the Iraqi election, said Turkey was taking its own precautions over Kirkuk, but declined to give details.
Turkish Foreign Minister Abdullah Gul said Turkey could not stand passively by if Kurds took control of Kirkuk, although he stopped short of saying Ankara would send troops into Iraq.
"Our borders are clear. We have no territorial designs," he told the English-language newspaper Turkish Daily News. But he added: Sometimes you may not wish to embark on a road but developments force you to take certain actions ... In democratic countries, governments don't have the luxury of ignoring public sentiment."
American excuse blasted
Erdogan also took the US to task for failing to crack down on an estimated 5000 Turkish Kurdish fighters holed up in the mountains of northern Iraq.
"Their excuse is that they are overwhelmed [in Iraq] but they accept that our demands are just demands and have promised they will deal with it. We have not yet seen action," said Erdogan.
Ankara blames fighters of the Kurdistan Workers Party (PKK) for the deaths of more than 30,000 people during a 20-year armed struggle to carve out a Kurdish state in southeastern Turkey.
Both Kirkuk and the PKK are expected to feature high on the
agenda in Ankara on Monday in talks between Turkish officials
and the Pentagon's outgoing undersecretary of defence for policy, Douglas Feith, a key architect of the Iraq war.