Washington: Iran is "complicit, in a broad sense," in Hamas attack in which at least 900 Israelis were killed, White House National Security Adviser Jake Sullivan said here on Tuesday.

"We've said since the beginning that Iran is complicit in a broad sense because they have provided the lion's share of the funding for the military wing of Hamas, they've provided training, they have provided capabilities, they have provided support and they've had engagement and contact with Hamas over years and years, and all of that that has played a role in contributing to what we have seen," Sullivan said, adding, "Now, as to the question of whether Iran knew about this attack in advance or helped plan or direct this attack, we do not, as of the moment I'm standing here at the podium, have confirmation of that."

Sullivan's remarks came after US President Joe Biden denounced the attacks on Israel as "pure unadulterated evil," saying the stated purpose of the terrorist organisation Hamas is "to kill Jews."

NSA Sullivan told reporters that the administration was engaged with its Israeli counterparts and "looking back through our intelligence holdings to see if we have any further information on that," adding, "If there's an update to that, I'll share it with you."

"But as I stand here today, while Iran plays this broad role, this sustained, deep and dark role in providing all of this support and capabilities to Hamas, in terms of this particular gruesome attack on October 7, we don't currently have that information," he added.

Asked why Israel was unable to anticipate Hamas' attack on Israel, Sullivan referred questions to Israeli officials, however, as for the US, he said, "We did not see anything that suggested an attack of this type was going to unfold any more than the Israelis did."

The US State Department on Tuesday said that Secretary Antony Blinken will travel to Israel "to engage our Israeli partners directly about the situation on the ground."

"Secretary of State Antony J Blinken will travel to Israel and Jordan October 11-13, 2023, where he will meet with senior officials," said the US Department of State in a statement.