Jets from Russia and Belarus will hopefully make a key difference in the fight against ISIS in Iraq, the country’s Prime Minister Nouri Maliki said. He expressed regrets over Iraq's contract with the US, saying their jets are taking too long to arrive.

"God willing within one week this force will be effective and will destroy the terrorists' dens," he told BBC Arabic.

Meanwhile, Maliki criticized the process of purchasing US jets as “long-winded,” adding that the radicals could have been repelled if Iraq had proper air defense.

"I'll be frank and say that we were deluded when we signed the contract [with the US]," Maliki said. "We should have sought to buy other jet fighters like British, French and Russian to secure the air cover for our forces; if we had air cover we would have averted what had happened," he went on.

Maliki said Iraq bought second-hand jet fighters from Russia and Belarus "that should arrive in Iraq in two or three days.”

The radical Sunni Islamic State in Iraq and the Levant (ISIS or ISIL) has taken large parts of the country's north from the Shia government.

During the interview, the prime minister also confirmed that Syria was behind Tuesday’s air strikes that targeted Iraqi rebels, adding that he welcomed the move.

"They carry out their strikes and we carry out ours and the final winners are our two countries," he said.

On Tuesday, unidentified bombers launched an air strike on ISIS positions in the northern Iraqi city of al-Qaim.

Iraq’s own air force has also been carrying out attacks on insurgent strongholds over the past week.

On Monday, radical Sunni militants regained control over the northern city of Tal Afar and an airport. A day earlier, jihadists captured three new towns and two border crossings – one with Jordan and the other with Syria.

The ongoing offensive by ISIS is aimed at achieving total dominance in Iraq by radical Sunni militants.

Hundreds of Iraqi soldiers have been killed by the insurgents since June 9, when the Sunni militants started their offensive, according to Iraqi forces.

The United Nations says more than 1,000 people – mainly civilians – have been killed during the surge thus far.