Up to 450 additional U.S. troops will head to Iraq to train local security forces in their war against ISIS, the terrorist group that controls large swaths of territory across that nation and neighboring Syria, the Los Angeles Times reported.

President Barack Obama, who ordered the move on Wednesday, also directed the U.S. Department of Defense to expedite the delivery of "essential equipment and materiel" to Iraqi forces, including Kurdish Peshmerga troops in northern Iraq and local tribal fighters in eastern Anbar province, White House Secretary Josh Earnest noted in a statement.

The moves signal "a major shift of focus in the fight against the Sunni militant group" on the part of the White House and follow months-long, behind-the-scenes discussions about how prominently plans to retake Mosul should figure in the early phase of the military campaign against the militants, the New York Times noted.

Mosul, a city of more than a million inhabitants some 400 km north of the Iraqi capital, Baghdad, had fallen to the ISIS last year. In the midst of its announcement, the administration "took pains to assert that the steps did not constitute a change in strategy," the newspaper editorialized.

"This decision does not represent a change in mission, but rather adds another location for (the Department of Defense) to conduct similar activities in more areas in Iraq," the Pentagon insisted in a statement. "This effort is in keeping with our overarching strategy to work with partners on the ground to degrade and ultimately defeat (ISIS)," the department added.

The decision will put American troop levels in Iraq up to 3,550 and the additional soldiers will arrive as early as this summer, an unnamed U.S. official told the New York Times. American personnel will focus on training Sunni fighters with the Iraqi army, the source added.

Earnest noted that the administration sought to "leverage all instruments of power to counter (ISIS) globally and, most importantly, to protect the U.S. homeland," according to the Los Angeles Times.

"Thousands of foreign fighters ... have joined (ISIS) in Syria and Iraq," Earnest said. "We remain concerned that these trained fighters will return to their home countries and carry out attacks and seek to inspire supporters to conduct attacks at home," he added.