On Thursday, President Joe Biden said the assassination of Hamas leader Ismail Haniyeh will make ceasefire negotiations all the more difficult.

As Hamas’s political chief, Haniyeh had engaged in ceasefire talks. Biden has been under immense pressure from his party to push Israel and Prime Minister Benjamin Netanyahu to make a deal with the terrorist organization that would slow hostilities in Gaza and include the exchange of hostages. However, the successful assassination of Haniyeh in Tehran outraged Iran, which is vowing it will seek retaliation against Israel.