US Secretary of State Antony Blinken called on Israel to limit Palestinian civilian deaths in the Gaza Strip.
Addressing a press conference in Qatar, Blinken said: "We have urged the Israelis to use every possible precaution to avoid harm to civilians.
"We recognise many Palestinian families in Gaza are suffering through no fault of their own and that Palestinian civilians have lost their lives," he said.
Blinken defended the Israeli offensive stressing that Israel was "within its rights after the unconscionable attacks by Hamas."
After a visit to Tel Aviv, Blinken started his six-nation tour of Arab countries.
He praised Qatar, which has longstanding relations with Hamas for showing urgency in efforts to persuade it to free an estimated 150 hostages.
But he warned about the close US partner's strong ties with Hamas, which has an office in Doha, where Ismail Haniyeh largely resides.
"There can be no more business as usual with Hamas," Blinken said.
Qatar's Prime Minister Mohammed bin Abdulrahman Al-Thani however defended the Hamas office, saying it served the purpose of communication.
Israel called on more than one million people to evacuate ahead of an expected ground invasion.
However, US officials also appeared to backtrack on earlier efforts to let Gazans flee to neighbouring Egypt, saying they did not see wide support and instead wanted the safe areas within Gaza.
The United States is meanwhile working with both Egypt and Israel to let Americans and other foreign nationals leave through the Rafah border crossing, the US official said.
Humanitarian corridors
Blinken opened the day consulting in Amman with King Abdullah II as well as Palestinian President Mahmud Abbas.
The Jordanian king, a longtime US partner, called for ‘humanitarian corridors’ to bring relief into Gaza and de-escalate the situation, a statement from the royal court said.
Abdullah, whose kingdom is home to two million Palestinian refugees, warned against another permanent displacement, this time from Gaza.
"The crisis should not be spread to neighbouring countries and exacerbate the refugee issue," the king told Blinken.
After Qatar, the top US diplomat made a stop in Bahrain, meeting with Prime Minister and Crown Prince Salman bin Hamad Al Khalifa. He is also visiting Saudi Arabia, the United Arab Emirates and Egypt on his tour.
Hamas shocked Israel by breaching its southern border and killing more than 1,300 people, including children, the elderly and revellers at a music festival.
Even before an expected ground operation, Israel has killed at least 1,799 people in relentless strikes on the Gaza Strip since the Hamas attack and has cut off food, water and electricity.