The White House announcement comes after Israel said on Friday it would keep troops in Lebanon's south beyond the Sunday deadline set out in a US-brokered ceasefire that halted war with Hezbollah.
"The arrangement between Lebanon and Israel, monitored by the United States, will continue to be in effect until February 18, 2025," the White House said in a statement.
Israeli forces killed 22 people in south Lebanon on Sunday as a deadline for their withdrawal passed and thousands of people tried to return to their homes in defiance of Israeli military orders, Lebanese authorities said.
Lebanon's US-backed military, which reported one of its soldiers among those killed by Israeli forces on Sunday, has accused Israel of procrastinating in its withdrawal.
The Hezbollah-Israel conflict was fought in parallel with the Gaza war, and peaked in a major Israeli offensive that uprooted more than a million people in Lebanon in 2024 and left the Iran-backed group badly weakened.
Israel has not said how long its forces would remain in the south, where the Israeli military says it has been seizing Hezbollah weapons and dismantling its infrastructure.
Israel said its offensive against Hezbollah aimed to secure the return home of tens of thousands of Israelis who were forced to leave homes at the border by Hezbollah rocket fire.
Hezbollah opened fire in support of its Palestinian ally Hamas at the start of the Gaza war on October 8, 2023.
The White House on Sunday also said the governments of Lebanon, Israel and the US would begin negotiations for "the return of Lebanese prisoners captured after October 7, 2023."
With AP