Iraq's top court has ordered the suspension of the Kurdistan Regional Government's (KRG) planned referendum on independence.

The Supreme Court declared the ruling on Monday, which calls for all preparations for the September 25 vote to be halted, following a review of multiple "requests to stop the referendum".

"The supreme court has issued the order to suspend organising the referendum set for September 25 ... until it examines the complaints it has received over this plebiscite being unconstitutional," it said in a statement.

Haider al-Abadi, Iraq's prime minister, had previously demanded the suspension of the referendum.

Al Jazeera's Hoda Abdel-Hamid, reporting from Erbil, said: "So far there has been no reaction after the court order, but this state order is very significant.

"What we see at the moment is that the Iraqi parliament is trying to use all the legal mechanisms that exist in this country and say that the referendum is against the constitution, which the Kurds have signed and helped write in 2005."

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At least three legislators have filed complaints against the planned vote, a parliamentary source told Reuters News Agency.

"We have received several complaints, and this is why we decided to suspend the referendum," said Ayas al-Samouk, a court spokesman.

The KRG, which governs the semi-autonomous Kurdish region in northern Iraq, has said a pro-independence vote would not trigger an immediate secession.

Massoud Barzani, president of the KRG, said a "yes" result would instead kick-start "serious discussions" with Baghdad.

Al Jazeera's Abdel-Hamid said the court's decision has left Barzani in a "very delicate position" politically.

"If he is to turn around and tell people that 'we [The KRG] will postpone the referendum', he needs something in return.

"At this point, you have to remember that the background to all of this is a really sour relationship between Erbil and Baghdad for some time now, even though there has been some military cooperation in the fight against the Islamic State of Iraq and the Levant (ISIL, also known as ISIS)."

The Iraqi government and several other countries, including the United States and Turkey, have opposed the referendum.