The United Nations says it will not be “engaged in any way or form” in the process surrounding the independence referendum in Iraq’s northern semi-autonomous Kurdish region that’s planned for September.

The statement by the U.N. special mission to Iraq, or UNAMI, could cast doubts on the credibility of the vote, which has already sparked wide criticism from the central government in Baghdad and several Western nations.

UNAMI’s statement was released late on Wednesday.

The president of the Kurdish region, Masoud Barzani, last week said the vote will determine whether the Kurdish region would secede from Iraq.

The vote is to be held in three governorates that make up the Kurdish region and also in areas that are contested by both the Kurds and the central government.