ANKARA, Turkey — Turkey's military chief vowed Wednesday to respond with more force to any further shelling from Syria, keeping up the pressure on its southern neighbor a day after NATO said it stood ready to defend Turkey.

Gen. Necdet Ozel was inspecting troops who have been put on alert along the 910-kilometer (566-mile) border with Syria after a week of cross-border artillery and mortar exchanges escalated tensions between the neighbors, sparking fears of a wider regional conflict. Turkey has reinforced the border with artillery guns and also deployed more fighter jets to an air base close to the border region since shelling from Syria killed five Turkish civilians last week.

"We responded and if (the shelling) continues, we will respond with more force," the private Dogan news agency quoted Ozel as saying during a visit to the town of Akcakale, where he offered condolences to a man who lost his wife and three daughters to a Syrian shell.