White House says Biden is 'frustrated' with Netanyahu but won't confirm if ... trends now

President Joe Biden is frustrated with Israel after the strike that killed aid workers for the World Central Kitchen but the White House won't say if he'll call Prime Minister Benjamin Netanyahu to express his disappointment. 

When National Security Council spokesman John Kirby was asked about the president's thinking of the attack, he said: 'I think you could sense the frustration in that statement yesterday.'

Biden described himself as 'outraged and heartbroken' in his statement condemning the attack. He also called for an investigation into the incident.

Kirby said the administration would let Israel finish its investigation of the incident and read out its conclusions.

'They have already admitted that they conducted this strike. They have already publicly said that their fault for this strike, and they're working their way through the specific findings and details and I think we need to let them finish that work and speak to it themselves,' he told reporters on Wednesday.

He also pointed out that 'I don't think you can look at what we've been saying, what we've been doing, or even the President's statement last night and say that we've somehow gone easy on Israel in every regard.'

Biden and Netanyahu's relationship has gotten more and more tense as Israel's war against Hamas has continued. The administration is under heavy pressure from home and abroad to ensure the safety of aid workers and get critical supplies to the Palestinian people, many of whom are facing famine.

But, on Tuesday, Biden joined a chorus of world leaders furious over the drone strikes that killed the WCK aid workers in Gaza, including one American.

Biden said Israel 'has not done enough to protect aid workers trying to deliver desperately needed help to civilians' as thousands of Palestinians are caught in the crosshairs of war and left without food, water and other necessary supplies.

The president called for a 'swift' investigation to bring accountability to what he said was not a 'stand alone incident'.

Israel apologized for what it called 'a grave mistake' and said it is investigating the incident.

International outrage ensued after the convoy of aid workers for World Central Kitchen was hit by an Israeli 'triple tap' drone strike on Monday, leaving seven dead. The three cars were marked as humanitarian aid and were struck while moving along a route approved by the Israel Defense Forces (IDF).