Matthew Miller, the US State Department spokesman, made these remarks.
According to him, if Tehran refuses to cooperate with IAEA observers, Washington and its allies are prepared to put more pressure on Iran.
"If the Iranian regime implements these programs, we will respond accordingly. The Iranian regime must cooperate with the International Atomic Energy Agency without further delay and to fully fulfill its legal obligations," Miller warned.
It should be recalled that "Reuters" reported statements from European diplomats claiming that Iran increased the amount of uranium enrichment at the facilities in Fardo and Natanz in reaction to the resolution the IAEA Board of Trustees passed last week criticizing the country.
GunazTV