Iraqi Prime Minister Nuri al-Maliki is monopolising power and preparing the ground for a return to dictatorship, Kurdish leader Massud Barzani charged in an interview published on Sunday.

"Iraq is moving towards a catastrophe, a return to dictatorship," said Barzani in the interview published in pan-Arab newspaper, Al-Hayat, adding that it was "unacceptable" that Maliki was also Iraq's "defence minister, interior minister, intelligence chief and commander of the armed forces."

Barzani, who was received at the White House on Wednesday, said on his return to Arbil he would call a meeting of Iraqi leaders to "save" Iraq which is facing a political crisis.

In Baghdad, Maliki's spokesman, Ali Mussawi, sharply criticised Barzani's remarks.

"There is an incomprehensible escalation from Mr Massud Barzani and it is rejected, and no one among the Iraqi people or others accepts it," he told AFP.

"Many different Kurdish leaders called us and informed us of their rejection of such tendencies, which could be useful to some factions that do not carry good intentions to the Iraqi and the Kurdish people," he said.

Iraq's political woes deepened after the central government in Baghdad issued in December an arrest warrant against Vice President Tareq al-Hashemi, a Sunni, accused of running a death squad.

Hashemi sought shelter in the autonomous Kurdistan region run by Barzani.

Barzani said the meeting he would call must come up with "radical solutions... specific timeframe to exit the crisis," and if it failed "we will take another decision" -- a reference to the possible secession of Kurdistan.

"This is not blackmail or a threat. I'm serious. I will put a referendum to the Kurdish people. Whatever the price, we will never accept a return to dictatorship in Iraq," Barzani said, referring to Saddam Hussein's rule.

Tensions have been running high between Maliki's Shiite National Alliance coalition, Iraqi Kurds and the Sunni-backed Iraqiya bloc to which Hashemi belongs, mainly over the distribution of the country's oil wealth.

Barzani said he refused to hand over Hashemi to the Baghdad authorities and would not ask him to leave Kurdistan, if he decides to return there after his current regional tour.

"I will not ask him to leave Kurdistan and I am not opposed to his return if he decides to return," he told Al-Hayat.

Hashemi arrived in the Sunni heavyweight kingdom of Saudi Arabia on Wednesday from Qatar, after a controversial four-day visit that sparked criticism from Iraq's Shiite-led government and demands that Doha hand him over.

Qatar refused those demands, saying they violated "diplomatic norms."

Elsewhere Al-Hayat quoted Barzani as saying an agreement with US energy giant ExxonMobile -- considered null and void by the Baghdad authorities -- was still valid.

"Rumours of the contract being cancelled are unfounded and were made under threat of the Iraqi government," he said.

ExxonMobil in mid-October signed an agreement for oil exploration with the autonomous region of Iraqi Kurdistan, earning the wrath of the Iraqi central government in Baghdad.

Baghdad does not recognise such agreements and so far has prevented any oil company having a contract with Kurdistan to participate in tenders in rest of the country.