US President Donald Trump told NBC News on Thursday he was "very optimistic" about a peace deal with Iran after their ceasefire, and that Israel was "scaling back" strikes in Lebanon.
Trump told the US broadcaster in a telephone interview that Iran's leaders were "much more reasonable" in private but added that "if they don't make a deal, it's going to be very painful."
Vice President JD Vance is due to hold talks with Iran in Pakistan on Saturday.
Israeli Prime Minister Benjamin Netanyahu had meanwhile agreed in a call with Trump on Wednesday to "low-key it" with Lebanon after devastating strikes on Wednesday, the US president said.
The Israeli military escalated attacks across Lebanon despite the two-week Washington-Tehran ceasefire brokered by Pakistan.
Israel carried out one of its largest strikes in Lebanon on Wednesday since launching a military offensive against Hezbollah early last month. The attacks have killed at least 254 people and wounded 1,165, according to Lebanon's Civil Defense.
The escalation has raised concerns about a potential renewed Israeli occupation of southern Lebanon, possibly extending to the Litani River.