US Secretary of State Antony Blinken said in his final news conference as secretary of state on Thursday that he was confident that a ceasefire in Gaza agreed upon by Israel and Hamas would begin on Sunday as expected despite a last-minute problem.

Blinken said in his final State Department press conference that he spoke to US negotiator Brett McGurk and Qatari officials on Thursday morning to resolve the issue.

"It is not surprising that we are facing an unresolved issue in what has been a difficult and risky process and negotiation... We are working to resolve this unresolved issue as we speak," he added.

Blinken said in response to reporters' questions that a ceasefire in Gaza could have been reached earlier.

Asked if the deal, had it been reached earlier, could have saved many lives, he replied: "Should this have happened months ago? Yes. Could it have happened months ago? Yes."

He added that Israel and Hamas had made decisions that complicated the situation, but stressed that "Hamas was in the first place," which he described as refusing to participate in recent months.

Despite the challenges, Blinken stressed that the United States was able to move the process forward and is now "on the verge" of reaching an agreement.

The Qatari Prime Minister announced that the mediation efforts made by Doha, Cairo and Washington resulted in an agreement between Israel and Hamas.

Hamas on Wednesday agreed to the deal, which is expected to be implemented in three stages starting on Sunday.

A number of protesters interrupted the US Secretary of State inside the State Department press conference room during his press briefing, which led to his confusion and stopping him from proceeding with his presentation and answer.

As he spoke, a journalist interrupted him and accused him of genocide and working for the "Zionist lobby," while another journalist shouted, "You are a criminal, a criminal! Your place is in The Hague," referring to the headquarters of the International Criminal Court in the Netherlands.