The United States has ruled out any contact with an Iranian delegation at an upcoming international aid conference in London.
The conference on Afghanistan, which begins Tuesday, comes just two days before the United Nations' nuclear watchdog is expected to decide whether to refer Iran and its nuclear program to the U.N. Security Council.
The United States want the Council to levy sanctions against Tehran for its alleged breach of the Nuclear Non-Proliferation Treaty. In Washington, Under Secretary of State Nicholas Burns blamed Iranian President Mahmoud Ahmadinejad and his hardline nuclear stance for the no-contact policy. He also noted Iran's call for the destruction of Israel and its continued support for terrorism.
Ahead of the London conference, U.S. Secretary of State Condoleezza Rice is expected to meet with other permanent members of the Security Council and Germany for a strategy session on Iran.