Twenty-one hours was not enough to end 47 years of hostility between Iran and the US, writes the BBC's Lyse Doucet.

Many issues could derail the truce and the negotiations aimed at making a broader deal to stop the fighting permanently.

Even if the talks fail to produce a deal, a return to an all-out war may still be averted.

Neither side indicated what will happen after the 14-day ceasefire expires on April 22.

Iran-U.S. talks in Pakistan end without a deal, citing excessive American demands and unresolved key issues, officials report.

US-Iran talks in Islamabad end without a deal, with each side blaming the other for the failure.

Iran and the US reached an understanding on a number of issues, but views diverged on two or three important issues, Iranian Foreign Ministry Spokesperson Esmaeil Baghaei stated

Verhandlungsmarathon, aber kein Deal - die Kriegsparteien Iran und USA konnten sich vorerst nicht auf einen Weg zum Frieden einigen. Gehen die gegenseitigen Angriffe nun wieder…

US VP JD Vance says Iran chose not to accept US terms, while Iran says it did not expect a deal at the first meeting.

Talks between Iran and the US expose deep divisions, prolonging uncertainty during a two-week ceasefire.

Twenty-one hours was not enough to end 47 years of hostility between Iran and the US, writes the BBC's Lyse Doucet.

Two sides tested one another’s resolve but timeframe meant it was probably unrealistic to expect deal

JD Vance blames collapse on failure to agree on Tehran’s nuclear capabilities

US and Iran end marathon Islamabad talks without agreement, leaving fragile ceasefire under growing strain.