U.S. Secretary of State Antony Blinken, second from right, returns to his hotel in the Saudi capital Riyadh after meeting with Saudi Crown Prince Mohammed bin Salman, Oct. 15. AFP-Yonhap

U.S. Secretary of State Antony Blinken on Sunday said he held a "very productive" meeting with Saudi Crown Prince Mohammed bin Salman in Riyadh, a critical diplomatic engagement as Israel prepared to launch a ground assault in the Hamas-controlled Gaza Strip and Washington worked to contain the conflict.

"Very productive," Blinken replied to a question from a Reuters reporter as he returned to the hotel where the U.S. delegation was staying.

A U.S. official said the meeting lasted for just under an hour and took place at the Crown Prince's private farm residence.

"The Secretary highlighted the United States' unwavering focus on halting terrorist attacks by Hamas, securing the release of all hostages, and preventing the conflict from spreading," the State Department spokesperson Matthew Miller said in a statement.

"The two affirmed their shared commitment to protecting civilians and to advancing stability across the Middle East and beyond," Miller added.

The top U.S. diplomat's meeting on Sunday with the Kingdom's de-facto ruler comes as the region is on the brink of a further escalation with Gaza, a small coastal enclave home to 2.3 million Palestinians, bracing for Israel's ground offensive.

Blinken has embarked on his most extensive trip to date to the Middle East, working with Arab allies to prevent the war from spiraling into a wider conflict and help secure the release of hostages kidnapped by Hamas militants.

Israel has vowed to annihilate the militant group Hamas in retaliation for a rampage by its fighters in Israeli towns eight days ago in which its militants shot men, women and children and seized hostages in the worst attack on civilians in the country's history.

Late on Saturday, Iran warned of "far-reaching consequences" if Israel's bombardment was not stopped.

Israeli Prime Minister Benjamin Netanyahu's government also told the militant group Hezbollah in Lebanon, which neighbors Israel to the north, not to start a war on a second front, threatening the "destruction of Lebanon" if it did.

Blinken started his tour on Thursday in Israel, voicing robust U.S. support for Washington's closest Middle East ally in its war against Hamas.

Since then, he has visited Jordan, Qatar, Bahrain, Saudi Arabia. He made a brief visit to the United Arab Emirates and returned to Riyadh to meet the Crown Prince late on Saturday, although the meeting only materialized on Sunday morning.

He is expected to travel to Egypt later on Sunday.

Gaza authorities said more than 2,300 people had been killed, a quarter of them children, and nearly 10,000 wounded. Rescue workers searched desperately for survivors of nighttime air raids. One million people had reportedly left their homes.

Blinken on Saturday met Saudi Foreign Minister Prince Faisal Bin Farhan in Riyadh. Before their meeting, Blinken said protecting civilians on both sides of the conflict was vital.

"And we're working together to do exactly that, in particular working on establishing safe areas in Gaza, working on establishing corridors so that humanitarian assistance can reach people who need it." (Reuters)