Turkey, Iran, and Iraq have threatened unspecified "countermeasures" if Iraq's Kurdish leaders go ahead with a planned referendum on independence.

The three countries' foreign ministers met on September 20 on the sidelines of the UN General Assembly in New York, ahead of the nonbinding referendum scheduled for September 25.

In a joint declaration released by the Turkish Foreign Ministry, Mevlut Cavusoglu of Turkey, Ibrahim al-Jaafari of Iraq, and Mohammad Javad Zarif of Iran reaffirmed their countries’ commitment to Iraq's territorial integrity and "unequivocal opposition” to the referendum.

Kurdish leaders want to hold the vote in Iraq’s Kurdish autonomous region and neighboring areas on September 25, despite opposition from the Baghdad government and the international community.

Iran and Turkey have also vehemently opposed the referendum amid fears that it could encourage their Kurdish minorities to break away.

Calling the planned vote "unconstitutional," the ministers of Turkey, Iran, and Iraq agreed to “consider taking countermeasures in coordination," according to the statement.

They said the planned referendum would "not be beneficial" for the Kurds of Iraq and would put Iraq's gains against the extremist group Islamic State "under great risk."