The Iranian delegation participating in talks in Switzerland has formally protested to the US side after President Donald Trump threatened to restart the war, according to media reports from Iran. Mr Trump's remarks came as Vice President JD Vance met Iranian officials for the first talks aimed at solidifying an interim peace deal at the Swiss resort of Burgenstock, with the participation of Qatari and Pakistani mediators. The talks were the first to be held under the terms of a deal agreed a week ago, overshadowed by Iranian claims that the Strait of Hormuz remained closed, and Israeli strikes on Lebanon. Quadrilateral talks involving Iran, the US, Qatar and Pakistan in Switzerland were suspended after about 80 minutes of discussions to allow the delegations to hold internal consultations, Iran's Fars News Agency reported. According to Iranian media reports, the Iranian delegation conveyed its objections to the US side and was considering options for what it described as an appropriate response to Mr Trump's recent verbal threats."Iran must immediately stop their highly paid PROXIES in Lebanon from causing trouble. If they don't, we'll hit Iran very hard again, just like we did last week, only harder!!!" Mr Trump said, referring ⁠to Hezbollah, and to an escalation he ordered earlier this month.Fox News reported that Trump had gone further in an interview, saying that he had told Iranian officials they wouldn't "have a country" if they closed the strait, and threatening to take over the waterway.Iranian parliament Speaker and lead negotiator Mohammad Bagher Ghalibaf warned the US to be "careful" with statements and said the country's armed forces were ready to respond.Play02:57Eight unresolved issues in the US-Iran deal"They better be careful with their statements, our armed forces are ready to respond in another way. Whatever they say, we are the ones who will act," he said on X after Mr Trump threatened to resume the war on Iran if Hezbollah was not brought under control in Lebanon.Iranian media reports suggested the Iranian negotiating delegation had left the venue of the talks in protest against Mr Trump's remarks, but it was not known if that was true as the talks had already ended. The semi-official Tasnim News Agency cited a source close to the team who said that the delegation had left due to the threats being a "gross violation" of the first point of the interim deal, which states that both sides must "refrain from the threat or use of force against each other." Axios quoted a diplomat involved in the talks as saying the delegation had not departed. In Switzerland, Mr Vance had downplayed the impact of the war in Lebanon and claimed progress had been made towards ending the fighting. “We've seen great progress over the last couple of days in ensuring that the ceasefire holds in Lebanon,” he said, adding that Mr Trump was committed to achieving a broader regional ceasefire.He also said that Mr Trump wanted to "turn over a new leaf" in relations with Iran if Tehran abandons policies that Washington views as destabilising, striking a different tone to that of the US President, who was threatening to attack the country. The venue for the Lake Lucerne talks. Getty ImagesInfoThere was no joint photo of the Iranian and American representatives. Footage showed Iran's Foreign Minister Abbas Araghchi briefly walk into the room to speak to the Pakistani Prime Minister Shehbaz Sharif, but he did not interact with Mr Vance.Overshadowed by LebanonDespite the announcement of a ceasefire in Lebanon on Friday, intense fighting and Israeli attacks continued over the weekend. Earlier, Iran's Foreign ‌Ministry spokesman Esmail Baghaei said that, because Washington had failed to guarantee a ceasefire in Lebanon, the meeting would cover only the enactment of the agreement itself and not the substantive issues foreseen for the next stage.Tasnim News Agency reported that any negotiations could be halted if Israel does not withdraw from Lebanon, saying Iran would enter a “tough response phase” amid continued occupation and Israeli actions.Iranian State TV said the talks had focused on Lebanon and on putting the interim deal into effect. It said that, contrary to some foreign media reports, no negotiations regarding Iran’s nuclear programme had taken place during the first 80-minute round of talks.