US President Donald Trump has warned Iran to stop supporting Hezbollah activities in Lebanon, threatening fresh military action if unrest continues.

The warning came as senior US and Iranian officials opened peace talks in Switzerland amid recent clashes between Israeli forces and Hezbollah in southern Lebanon that have raised concerns over regional stability.

US Vice President JD Vance said progress had been made in maintaining the ceasefire in Lebanon, expressing optimism that ongoing diplomatic efforts could help secure lasting peace in the region.