Lebanese soldiers have shot and captured a man who fired at the US embassy in Beirut on Wednesday, according to Lebanon's military.

Local media reported that gunfire was exchanged with the assailant, only identified as a Syrian national, for roughly 30 minutes before his arrest.

The US embassy said security was mobilised quickly during the attack, and that none of its staff members were injured.

Tensions in the region have been simmering, after cross-border attacks between Israeli forces and the Lebanese group Hezbollah - linked to the war in Gaza.

The months-long violence across the Israeli-Lebanese border has displaced thousands of people on both sides.

Israeli Prime Minister Benjamin Netanyahu threatened "very strong action" against Hezbollah during a visit to the border area on Wednesday.

The assailant shot by the Lebanese military was wearing a bloodied black vest with the words “Islamic State” written in Arabic and the English initials “I” and “S", according to local media.

The motive for the attack on the heavily guarded building remains unclear.

The Lebanese military only mentioned one person involved, who was wounded and taken to hospital.

However, reports have suggested there were multiple suspects, including a driver and three who opened fire.

Lebanese caretaker Prime Minister Najib Mikati's office said the PM had been informed about the incident, adding that the situation was stable and investigations were under way.

The Lebanese military said it had deployed troops around the embassy and surrounding areas.

A deadly bombing of the US embassy in Lebanon in 1983 killed 63 people, prompting officials to move its location from central Beirut to Aukar, a northern suburb.

Tension around the diplomatic headquarters has escalated in the wake of the Israel-Gaza war.

In October, hundreds of protesters clashed with Lebanese security forces around the embassy to express their anger over Gaza's mounting death toll.