US troubled by Iran's stance on missile talks

US Secretary of State Marco Rubio warned Wednesday that Iran's refusal to discuss its ballistic missile program poses "a big problem."

"It's also important to remember that Iran refuses, refuses to talk about the ballistic missiles to us or to anyone, and that's a big problem," he said, speaking to reporters on the Caribbean island of St. Kitts, where he attended a meeting of the leaders of the Caribbean Community (CARICOM).

The comments come amid heightened tensions between the US and Iran, driven by disputes over Tehran's missile development and nuclear ambitions and renewed indirect talks in Geneva to address those issues.

Washington has pressed for limits on Iran's ballistic missile program alongside restrictions on nuclear enrichment, a demand that Tehran has so far resisted.