U.S. Secretary of State John Kerry is warning Iran to come to nuclear talks prepared to deal seriously with world powers regarding concerns over its nuclear program.
Kerry said that Iran knows what it needs to do to prove its nuclear intentions are peaceful, as it claims.
If it does, Kerry said, the international community is prepared to respond positively. If not, he says, it will only face increased international isolation. Kerry said the choice is purely up to Iran.
Kerry's comments in Washington come ahead of a meeting between Iran and senior officials from the five permanent members of the UN Security Council and Germany on February 26 in Kazakhstan.
They also come a week after U.S. Vice President Joe Biden offered to hold direct bilateral talks with Iran on resolving the standoff over its nuclear program.
On February 7, Iranian Supreme Leader Ayatollah Ali Khamenei rejected Biden's offer as a U.S. ploy.
Earlier this week, the United States tightened sanctions on Iran's access to its oil revenues, which have already been crimped by previous sanctions.
Based on reporting by AP and dpa