Lebanese militant group Hezbollah said its field commanders are ready to respond to an Israeli attack.
On Saturday, the leader of the group said Israel must be held accountable for an alleged drone attack and that Hezbollah was prepared for a confrontation.
Tensions have heightened in the last week after two drones crashed in southern suburbs of Beirut — an area dominated by Hezbollah.
The group accused Israel of flying the explosive-laden drones into their stronghold, landing one of them on the roof of Hezbollah's media office.
Leader Sayyed Hassan Nasrallah said this was a violation of Lebanon's sovereignty and that all options were open in response to the attack.
In a televised speech, he said Israel "must pay a price" and that "all threats and intimidations will not prevent the retaliation of the resistance."
He assured supporters that the group was prepared as tensions mounted: "We have as many precision-guided missiles in Lebanon, as we need for any confrontation, small or big."
The Israeli military says Hezbollah has an estimated arsenal of 130,000 rockets and missiles.
Israeli forces were seen positioned at the border with Lebanon in the past week. The military's Twitter account posted footage of tanks and ground troops being deployed.
Israel has identified Hezbollah as the most potent military threat on its borders.
The two fought a monthlong war in 2006 after Israeli soldiers were captured in a cross-border raid by Hezbollah.
Nearly 1,200 Lebanese nationals were killed, most of whom were civilians, as well as 158 Israelis.