In a CNN interview, Aoun said "the people of Lebanon are paying the price ... for the sake" of Iran's interests, and were "fed up" with war between Israel and Hezbollah - comments reflecting deep divisions along Lebanon's confessional and political fault lines.
"They are using Lebanon as a bargaining chip in their negotiation with the United States," Aoun said of Iran, according to excerpts of the interview published on the CNN website on Friday.
"It's unacceptable."
Shi'ite Muslim Hezbollah, founded by Iran's Revolutionary Guards in 1982, ignited the latest hostilities more than three months ago when it opened fire in solidarity with Tehran as Iran came under US-Israeli attack.
Aoun, who led the Lebanese military before becoming head of state, is a Maronite Christian, as required by Lebanon's sectarian power-sharing arrangements.
He has pressed for the peaceful disarmament of Hezbollah since being elected head of state by parliament in 2025.
Early in the war, he called for face-to-face talks with Israel, further setting him at odds with the group.
Iran has made a Lebanon ceasefire a condition for any peace deal with Washington in the wider regional conflict that began with the US-Israeli attack on Tehran on February 28.
In the US, Trump's special envoy Steve Witkoff and son-in-law Jared Kushner travelled to the Oak Ridge National Laboratory in Tennessee on Thursday to consult with experts who could play a role in nuclear negotiations with Iran, a source familiar with the trip said on Friday.
The source, confirming an Axios report, did not provide additional details.
Trump is adamant any deal to end the war with Iran includes a provision that Tehran will not develop a nuclear weapon.
Iran is believed to possess about 408kg of highly enriched uranium that was at sites bombed by US planes a year ago.
Tehran has been adamant it must maintain the ability to enrich uranium and denies developing a weapon.
On Thursday, Hezbollah rejected a ceasefire plan agreed by Lebanese and Israeli government officials in US-mediated talks in Washington.
The deal would be contingent on Hezbollah ceasing fire and its fighters withdrawing from southern Lebanon.
Hezbollah leader Naim Qassem said in a written statement on Thursday direct Lebanon-Israel talks in Washington were rejected by "broad segments of the Lebanese people".
"The Lebanese people are not your people," Aoun said, addressing Qassem.
Israeli attacks have killed thousands of people in Lebanon since March and displaced some 1.2 million people, Lebanese authorities say.
Israeli troops have occupied a swathe of southern Lebanon.
