US vice-president JD Vance said Washington is uncertain who makes decisions in Tehran. (EPA Images pic)

FAIRBANKS: US vice-president JD Vance said in an exclusive interview with Reuters that Iran must make a “meaningful” reduction in its nuclear enrichment capacity to satisfy US demands and end the countries’ seven-month war, even as Washington was unsure how Tehran makes decisions in negotiations.

Vance, a longtime sceptic of US involvement in foreign wars, has taken a leading role in negotiating a settlement to the conflict and brokered a provisional peace agreement in September that quickly fell apart.

The war has jolted global energy markets and become a political liability for president Donald Trump and fellow Republicans ahead of November midterm elections.