AN Iranian-American man who US officials say has links to Iran’s security forces pleaded not guilty in court last night to plotting to kill the Saudi ambassador to Washington in a bomb attack.

THE United States warned yesterday it would hold Tehran accountable after foiling an alleged high-level Iranian plot to kill Saudi Arabia’s ambassador to Washington.

The US has accused Iranian government agents of plotting to assassinate the Saudi ambassador, immediately using the thwarted plot to step up sanctions and recruit international allies in a bid to further isolate Tehran.

AGENTS of the Iranian government were last night accused of being involved in a plot to assassinate the Saudi ambassador to the United States, with help from a purported member of a Mexican drug cartel.

Two people have been arrested for conspiring to kill the US ambassador to Saudi Arabia, US officials say.