ANKARA, Turkey — Turkey signaled Tuesday it would step up its engagement in the Syrian war, as Turkish-backed Syrian rebels massed along the border to assault one of the last Syrian frontier towns held by Islamic State militants.

Foreign Minister Mevlet Cavusolgu pledged “every kind” of support for operations against ISIS along a 62-mile stretch of Syrian frontier, putting the NATO member on track for a confrontation with U.S.-backed Kurdish fighters in Syria, who have been the most effective force against ISIS and who are eyeing the same territory.

Cavusolgu said Turkey would support twin operations stretching from the Syrian town of Afrin in the northwest, which is already controlled by Kurdish forces, to Jarablus, in the central north, which is held by the Islamic State group.

“It is important that the terror organizations are cleansed from the region,” Cavusolgu said in a joint news conference with his Hungarian counterpart.

Turkish artillery shelled Jarablus for the second consecutive day as reports circulated that Turkish-backed Syrian rebels were preparing to storm the town, a vital supply line and the last border point that directly connects the Islamic State group with Turkey and the outside world.

The Britain-based monitoring group said some 500 Syrian rebels were massed on the Turkish side of the border in preparation for an assault, including local fighters from Jarablus.

The latest developments have thrust the town into the spotlight of the ongoing Syrian civil war. Jarablus, which lies on the western bank of the Euphrates River where it crosses from Turkey into Syria, is one of the last important ISIS-held towns standing between Kurdish-controlled areas in northern Syria.

Located 20 miles from the town of Manbij, which was liberated from ISIS by Kurdish-led forces earlier this month, Jarablus would be a significant prize, linking up border areas under Kurdish control east and west of the Euphrates River.

Turkey has increased security measures on its border with Syria, deploying tanks and armored personnel carriers in recent days.

Turkey has vowed to fight ISIS militants at home and to “cleanse” the group from its borders after a weekend suicide bombing at a Kurdish wedding in southern Turkey killed at least 54 people, many of them children. Turkish officials have blamed ISIS for the attack. Ankara is also concerned about the growing power of U.S.-backed Syrian Kurdish forces, who it says are linked to Kurdish groups waging an insurgency in southeastern Turkey.

The Kurdish-led group known as the Syria Democratic Forces, or SDF, recaptured Manbij from ISIS earlier this month, triggering concerns in Ankara that Kurdish forces would seize the entire border strip with Turkey.