WASHINGTON, March 17: The White House on Wednesday played down suggestions that a new US dialogue with Iran could help resolve a growing controversy over Tehran's nuclear programme, just as US President George Bush prepared to meet the chief of the UN nuclear watchdog.

"We have not received any official proposals from Iran," White House spokesman Scott McClellan told reporters. "There are a number of serious concerns we have with regard to Iran ... that they need to work to address. Obviously, we've always said in the past that there are established channels of communication when we have issues of mutual concern to address."

Official US-Iranian contacts currently take place through Swiss diplomats who have acted as intermediaries since Washington severed ties with Tehran after militant students seized the US Embassy in the wake of the 1979 revolution.

Mr McClellan's remarks came hours before Mr Bush was scheduled to meet Mohamed ElBaradei, director-general of the International Atomic Energy Agency. Mr ElBaradei put forward the idea of a US-Iran dialogue at meetings this week in Washington, according to US sources.

The sources said he told US officials that dialogue could lead to a deal on the nuclear issue in exchange for a US move toward normalized ties with Tehran. The United States has accused Iran of developing nuclear weapons and has been pushing to put the issue before the UN Security Council for possible sanctions.

"Our policy toward Iran is quite clear, and has been quite clear," said Mr McClellan. "We continue to insist that Iran abide by all its IAEA and (nuclear Non-Proliferation Treaty) commitments, that it end the abuse of its citizens' human rights, stop supporting terrorism, halt meddling in its neighbours' internal affairs and turn over to their home governments the Al Qaeda terrorists it is now harbouring." -Reuters