The president of the Kurdish region of northern Iraq has asked his parliament to prepare for a referendum on independence, potentially paving the way for the break-up of the country.

Masoud Barzani, president of the Kurdistan Regional Government, called on parliament on Thursday to form an independent electoral commission that would start organising a referendum on independence for the semi-autonomous region.

"It will strengthen our position and will be a powerful weapon in our hands," he said.

Al Jazeera's Jamal Elshayyal, reporting from the regional capital Erbil, said the move was in line with the Kurds' march for self-determination.

Barzani's latest call is expected to anger Nouri al-Maliki, Iraq's prime minister, who is struggling to keep a grip on the country.

On Friday, Barzani issued a defiant statement to Baghdad that there was no going back on autonomous Kurdish rule in the oil city of Kirkuk.

The US has urged Barzani to stick with Baghdad, though Barzani said during a meeting last month with John Kerry, US secretary of state, that it was "very difficult" to imagine Iraq staying together.

The Kurdish region has long been at odds with Iraq's federal government on numerous issues, especially over what Kurdish politicians say are delayed and insufficient budget payments to the region.

But the issue is significantly complicated by the Kurds' control of Kirkuk and a chunk of other northern territory that they want to absorb, over the Maliki government's strong objections.

Speaking on Wednesday, Maliki accused the Kurds of "exploiting current events in order to impose a reality" and called the latest moves unacceptable.

Though calls for a referendum on independence are not new - Kurds strongly backed independence in a 2005 non-binding vote - the drastic change in the situation on the ground means the Kurds now see a fully sovereign state as within their grasp.

State within grasp

Iraq's five million Kurds, who have ruled themselves within Iraq in relative peace since the 1990s, have expanded their territory by up to 40 percent in recent weeks as a Sunni-led rebellion seized vast stretches of western and northern Iraq.

Saudi Arabia, who shares an 800km long border with Iraq sent 30,000 troops to guard its border after Iraqi soldiers withdrew from the area.

State news agency SPA said King Abdullah bin Abdulaziz ordered all necessary measures to protect the kingdom against potential "terrorist threats".

In Thursday's other developments, Sunni fighters released 32 Turkish lorry drivers captured in Mosul during an offensive across the north and west of the country.

Al Jazeera's Bernard Smith, reporting from Silopi, a Turkish district close to Iraq border, said the drivers were freed earlier in the day and were expected to fly back from Erbil.

Ahmet Davutoglu, Turkey's foreign minister, said the drivers were well but did not provide any details on the circumstances leading to their release.

Speaking in Ankara, he said efforts were under way to secure the release of the Turks still in captivity.

Fighters from the recently declared Islamic State seized the men on June 9. Three days later, they captured another 49 people from the Turkish consulate in Mosul.

"The critical process continues," he said. "Our prayers and our efforts will go on for the rest of them and God willing, we will share such good news about them too as soon as possible."