Israel-Gaza-Lebanon live updates: American hostage's father makes plea to Biden and Trump

Lebanese parliament speaker Nabih Berri said in a Wednesday address that the nascent ceasefire between Israel and Hezbollah is "a test for all Lebanese, from all sects, to save their country and protect its constitutional institutions."

Berri -- the leader of the Hezbollah-allied Amal Movement who has been negotiating on Hezbollah's behalf -- said the Lebanese "people were able to neutralize the effects of the Israeli aggression" and saluted late Hezbollah leader Hassan Nasrallah, who was killed in an Israeli airstrike in September.

"We call on all our displaced people in all our regions and the sister countries that hosted them to return," Berri added. "We are in dire need of national unity among all the Lebanese people."

Berri called for the "speedy election" of a new Lebanese president and thanked all those "who contributed to the ceasefire."

Hezbollah is yet to issue any official statement on the ceasefire, which went into effect at 4 a.m. local time Wednesday.

-ABC News' Ghazi Balkiz and Joe Simonetti

The Israel Defense Forces said Wednesday its troops fired on a vehicle carrying several people "in a zone prohibited for movement in Lebanese territory" shortly after the ceasefire came into effect at 4 a.m. local time.

"IDF troops fired to prevent them from advancing and the suspects left the area," the IDF wrote in a post to X.

The Israeli air force, it said "remains ready to act across Lebanese territory" while the Israeli air defense network "is also in a high state of defensive readiness."

"The IDF will act against anyone who tries to violate the ceasefire agreement and will not allow damage to the security of the residents of Israel," the force wrote.

-ABC News' Jordana Miller

Israel Defense Forces spokesperson Avichay Adraee said Wednesday morning that Lebanese civilians who fled their homes in the south of the country should not return to their homes until told to do so, despite the start of the ceasefire.

Twenty minutes after the ceasefire came into effect, Adraee said in a post to X that the IDF remains "positioned in its posts in southern Lebanon."

"Do not approach the villages that the IDF has evacuated or IDF soldiers in the area," he wrote. "For your safety and the security of your families, avoid entering the area."

"We will update you when it is safe to return to your homes," Adraee added.

-ABC News' Jordana Miller

The ceasefire went into effect at 4 a.m. local time Wednesday morning.

Representatives of Hezbollah still have not said anything on the record about the agreement.

When submitting the deal for approval, Prime Minister Benjamin Netanyahu said the deal still relies on the actions of Hezbollah.

"The duration of the ceasefire depends on what happens in Lebanon," Netanyahu said in the statement. "We will enforce the agreement and respond forcefully to any violation. We will continue together until victory."