The U.S. military spoke on Wednesday.

It said all American troops left Iraq.

This ends a 12-year mission.

The mission was against the Islamic State group.

The last troops left an air base in northern Iraq.

This was a deal between Baghdad and Washington.

President Donald Trump called the withdrawal "orderly."

It finished by a Sept. 30 deadline.

He said the U.S. was pulled into a "quagmire."

He said this change was a victory.

It was a victory for the U.S. and Iraq.

It was also a victory over the Islamic State group.

The two countries agreed to this two years ago.

Now there is a war between the United States and Iran.

This war sometimes comes into Iraq.

Iran-backed militias have fired on U.S. troops.

The U.S. has struck their strongholds.

Trump compared the Iran war to the Iraq war.

He said his one-day action in Venezuela was short.

He said the Iran war was short too.

He said fewer U.S. troops died.

Baghdad called the end of the U.S. mission a sign.

It shows Iraq is stronger and free.

Iran-backed groups also celebrated.

But some Iraqis fear the Islamic State group will come back.

This is true in the Kurdish region.

They also fear more attacks by Iran-linked groups.

Pentagon spokesperson Sean Parnell spoke.

He said troops and equipment finished an "orderly departure."

They left the Irbil air base.

He said the U.S. would still give training and intelligence help to Iraqi partners.

Iraqi Prime Minister Ali al-Zaidi led the handover ceremony.

He called the withdrawal the start of a "new phase."

This phase is about Iraq's freedom.

He said Iraqi forces would keep fighting the Islamic State group.

He said non-state groups would no longer hold weapons.

Trump praised al-Zaidi.

He said he had endorsed him.

But al-Zaidi was not on a ballot.

U.S. troops invaded Iraq in 2003.

They left in 2011.

They returned in 2014 to fight the Islamic State group.