U.S. and Western officials say world powers are prepared to accept an Iran nuclear agreement that doesn't immediately answer questions about past atomic weapons work — even though Washington has said those concerns must be resolved in a final deal.

The Obama administration said after a November 2013 interim accord that a comprehensive solution "would include resolution of questions concerning the possible military dimension of Iran's nuclear program."

Officials say that won't happen by a June 30 deadline, but a deal is still reachable.

Much of Iran's alleged atomic weapons work predates 2003. But Western intelligence agencies say they don't know for certain the extent of Iran's activities or if covert efforts have continued.

Talks continue over sites and scientists the U.N. wants access to for its investigation.