"We may do another little Epic Fury," Trump said in remarks at a rally in Florida as he spoke about the war. He did not elaborate.
Operation Epic Fury is the name used by the US military for its war against Iran.
Earlier on Friday, Trump said the US could end the war quickly but questioned whether Washington should seek a swift conclusion or allow the conflict to gradually wind down.
Speaking to reporters, Trump said oil is getting out through the Strait of Hormuz. "We are getting everything we want,' he said.
France's foreign minister warned any renewed escalation between Iran and the US would only have losers and raise oil prices.
"A further escalation between Iran and the United States would leave no winners and would likely have very serious consequences for hydrocarbon prices," Jean-Noel Barrot told reporters in Istanbul after a meeting with counterparts from Britain, Germany, Turkey, Egypt, Pakistan and Saudi Arabia.
Trump's warning comes amid reports Iran is stepping up efforts to target US diplomats and officials in the Middle East, including advanced plans for deadly attacks.
US news outlet Axios cited an intelligence memo sent to US Secretary of State Marco Rubio on Friday.
The intelligence assessments were among the reasons the US State Department was reducing staffing at embassies in the Middle East amid growing fears of a wider regional conflict, Axios reported.
On Friday, the State Department ordered a reduction in US personnel at embassies in the United Arab Emirates, Lebanon, Qatar and Jordan, according to the report.
CNN also reported the United States was seeking to withdraw some diplomats and their family members from diplomatic missions in those countries at short notice.
Separately, Iranian President Masoud Pezeshkian will travel to Russia next week to meet President Vladimir Putin.
In a post on Instagram, Foreign Minister Abbas Araghchi said the presidential meeting would follow up on discussions held during Russian Foreign Minister Sergei Lavrov's visit to Tehran earlier this week.
"Next week, these discussions and consultations will continue in Moscow with the participation of the presidents of both countries," Araghchi said.
The Iranian foreign minister said he had held extensive talks with Lavrov on bilateral relations and major regional and international issues.
The discussions focused on expanding political and economic co-operation, implementing existing agreements and strengthening the comprehensive strategic partnership between Tehran and Moscow, he added.
The meeting adds to signs that Moscow is positioning itself as both an ally of Tehran and a potential intermediary with Washington as diplomatic efforts remain deadlocked over Iran's nuclear program.
Earlier this month, Putin said Russia was prepared to do everything it could to help resolve the crisis and subsequently conveyed Tehran's position to Trump. Neither the contents of the message nor Washington's response was made public.
In Tehran on Tuesday, Araghchi said the two countries had "never" worked as closely as they do now with Lavrov describing Iran's cause as "just".
US-Israeli strikes on Iran and Israeli attacks on Lebanon have killed thousands and displaced millions.
with DPA and EFE
