By Ibrahim Salih  

BAGHDAD 

Acting U.S. Defense Secretary Pat Shanahan arrived in Iraq on Tuesday for an unscheduled visit for talks with Iraqi officials. 

According to a spokesman from the Pentagon, Shanahan met with Iraqi Prime Minister Adil Abdul-Mahdi and discussed the U.S. and Iraq's bilateral security relationship. 

"The partnership is focused on the mission of defeating ISIS, an effort supported by a global coalition of 74 nations," Cmdr. Sean Robertson said in a statement. 

The two leaders also discussed the further development of Iraqi security forces. 

"Secretary Shanahan reaffirmed the U.S. commitment to an independent, sovereign Iraq that is capable of defending itself," Robertson said. 

Shanahan was also set to discuss other issues of mutual interest, including the presence of U.S. troops in Iraq and the U.S. military pullout from Syria, a source with the Iraqi Foreign Ministry said on condition of anonymity because he was not authorized to speak to the media. 

Earlier this month, President Donald Trump said U.S. troops in Iraq were needed to observe Iran.  

Washington has around 5,200 troops in Iraq to provide training to Iraqi forces.  

Tuesday's visit is the first by Shanahan to Iraq since he took over as the acting Pentagon chief after the resignation of Defense Secretary James Mattis in December.  

In December, Trump visited U.S. troops in Iraq.

*Umar Farooq contributed to this report from Washington