BAGHDAD, Feb. 26 (Xinhua) -- The Iraqi government spokesman Monday said that lifting ban of international flights imposed earlier on airports of the semi-autonomous region of Kurdistan only depends on the security administration which must be subject to authority of the federal government.

The federal government confirms that the two airports (Erbil and Sulaimaniyah) are part of Iraq's sovereignty and thus they are part of the border crossings, which must be subject to the federal authority, the government spokesman Saad al-Hadithi said in a statement issued by the office of Prime Minister Haider al-Abadi.

Hadithi revealed that there is a negotiation going on in this regard, asserting "once this issue is resolved the ban will be cancelled and international flights will return to normal," according to the statement.

As for the three-month extension of the ban of international flights, Hadithi said "specifying a period of time is not problem, as once the negotiating teams between the federal government and the region reach to a final solution to the security administration of the two airports, the international flights will return as usual."

Earlier in the day, Talar Faiq, head of Erbil International Airport, told Kurdish Rudaw media net that the Iraqi federal authorities extended the suspension of international flights to and from the Kurdish airports to May 31, as the ban was supposed to expire on Wednesday.

The ban on international flights on the region's international airports of Erbil and Sulaimaniyah forced passengers to apply for an Iraqi visa to transit through Baghdad and Basra international airports to go or leave the Kurdish region.

In late September, the Iraqi federal government adopted the ban decision on the Kurdish region as part of a package of punitive measures that also included blocking all the border crossings, which are outside the control of the federal authorities.

Tensions have been running high between Baghdad and the region of Kurdistan after the Kurds held a controversial referendum on the independence of the Kurdistan region and the disputed areas on Sept. 25.

Baghdad government repeatedly expressed its stance that the Kurdish region must recognize Iraq's national sovereignty and abides by preserving its unity.

The independence of Kurdistan is opposed not only by the Iraqi central government, but also by other countries as it would threaten the integrity of Iraq and undermine the fight against IS militants.

Iraq's neighboring countries, especially Turkey, Iran and Syria, fear that the Iraqi Kurds' pursuit of independence threatens their territorial integrity, as large Kurdish populations live in those countries.