Fresh tensions emerged just as new U.S.-Iran talks opened in Switzerland. President Donald Trump warned Iran to rein in Hezbollah or face renewed military action, saying Washington could strike even harder than before. The remarks came hours after Vice President JD Vance stressed that a Lebanon ceasefire remains critical to any lasting Middle East settlement. With negotiators trying to preserve the recent memorandum of understanding, Trump's latest warning has raised questions over whether Washington and Tehran can keep the peace process alive while fighting continues along the Israel-Lebanon border.