Iran plane crash: Pompeo urges 'complete cooperation'

The United States on Wednesday urged "complete cooperation" with a probe into a Ukrainian flight's crash in Iran, which has rejected giving the Boeing plane's black boxes to arch-rival Washington.

"The United States calls for complete cooperation with any investigation into the cause of the crash," Secretary of State Mike Pompeo said in a statement, without naming Iran directly.

Pompeo offered condolences to the loved ones of the 176 people who were all killed on board, most of whom were Iranian or Canadian.

"The United States will continue to follow this incident closely and stands prepared to offer Ukraine all possible assistance," he said.

The crash came as the tense relationship between Iran and the United States had sharply worsened, with Washington killing one of Iran's top generals while he visited neighbouring Iraq.

Hours before the crash Iran had fired missiles at bases in Iraq housing US troops, but there was no immediate indication of foul play concerning the Ukraine International Airlines flight.

Ukrainian President Volodymyr Zelensky warned against "speculating" on the cause of the disaster, which is the latest in a string of mishaps involving a Boeing plane.

The head of Iran's civil aviation organization, Ali Abedzadeh, said that Iran would cooperate with Ukraine but not send the black boxes to the United States, which has no diplomatic relations with Tehran.

Under the rules of the International Civil Aviation Organization, of which Iran, Ukraine and the United States are all members, air crash investigations are led by the country where the accident occurred.

However, according to aviation experts, the countries that are capable of analysing black boxes are few -- notably Britain, France, Germany and the United States.