People carry Kurdistan flags during a May Day demonstration in Istanbul, Turkey, May 1, 2016. REUTERS/Murad Sezer

WASHINGTON (Reuters) - An Iraqi Kurdish leader sought on Friday to allay concerns an independence referendum would hurt the fight against Islamic State, after the U.S. State Department said the planned vote would distract from “more urgent priorities” like the defeat of the militant group.

Speaking in Washington, Masrour Barzani, head of the Kurdish government’s Security Council and son of President Barzani, said the government was committed to fighting “terrorism regardless of the political relationship with Baghdad.”

Barzani cited the Kurds’ role in fighting Islamic State. The Kurds play a major role in the U.S.-backed campaign to defeat the ultra-hardline Sunni Islamist group that overran about a third of Iraq three years ago and also controls parts of Syria.

The Sept. 25 vote could turn into another regional flashpoint and is likely to strain Iraq’s frayed federal unity. Neighbors Syria, Turkey and Iran, who also have sizable Kurdish populations, are all opposed to an independent Kurdistan in northern Iraq.

Germany, a major European ally for the Iraqi Kurds, has said it was concerned the referendum could exacerbate tensions in Iraq.

“Those opponents who say this is not the right time, my question to them is when is the right time? ... When ISIS invaded parts of Iraq and attacked Kurdistan, once again we were told it’s time of war so it’s not the right time. Now that ISIS is on the verge of collapse we are again being told it is not the right time,” he said.

While saying it appreciated the “legitimate aspirations” of the people of Iraqi Kurdistan, the State Department said last month it supports a “unified, federal, stable and democratic Iraq” and had voiced its concerns to Kurdish authorities.

The Kurds have been seeking an independent state since at least the end of World War One, when colonial powers divided up the Middle East, but their territory ended up split between modern-day Iraq, Syria, Turkey and Iran.