U.S. Defense Secretary Ashton Carter made an unannounced visit to Iraq early Thursday, even as the Iraqi military finalized plans to retake the city of Ramadi from the Islamic State group. This is Carter’s first visit to the Middle Eastern nation since he took office in February.

During his visit, Carter is expected to meet Iraqi Prime Minister Haider al-Abadi, local Sunni leaders and the U.S. troops currently deployed in Iraq, according to media reports. He would also assess the Iraqi military’s readiness to launch a successful offensive to retake Ramadi -- a strategic city in central Iraq that fell to ISIS in May.

Although Iraqi security forces took back the city of Tikrit, located about 87 miles northwest of Baghdad, in April, questions have been raised over their preparedness to launch an operation in Ramadi, where large number of civilians are believed to be trapped.  

According to a recent report by the United Nations, nearly 15,000 civilians have been killed in Iraq over the last 16 months. During their planned offensive, Iraqi forces, aided by Shiite militias, would aim to limit further civilian casualties.

“The urban terrain battles are among the most difficult,” Brig. Gen. Yahea Resool, a spokesman for Iraq’s defense ministry, reportedly said on Wednesday. “The forces who enter cities have to be highly trained.”

Currently, the U.S., in addition to having stationed approximately 3,600 troops to train Iraqi soldiers, is also carrying out airstrikes targeting cities held by the Sunni militant group. U.S. forces have already trained 9,700 Iraqi troops, including several units that are likely to participate in the Ramadi campaign.

“When conditions are right, we will transition into an assault to seize Ramadi,” Col. Steve Warren, a U.S. defense department spokesman, reportedly said, shortly before Carter arrived in Iraq. “This is classic maneuver warfare.”

The operation to retake Ramadi is likely to begin in the coming weeks, though the exact date has not been disclosed yet, according to media reports.