GAZA CITY, Gaza Strip • Israeli Prime Minister Benjamin Netanyahu vowed Wednesday to press ahead with an military offensive in the Gaza Strip, pushing back against calls from the United States to wind down the operation that has left hundreds dead.

Netanyahu’s tough comments marked the first public rift between the two close allies since the fighting began last week and could complicate international efforts to reach a cease-fire.

Israel continued to pound targets in Gaza with airstrikes, while Palestinian militants bombarded Israel with rocket fire throughout the day. In another sign of potential escalation, militants in Lebanon fired a rocket barrage into northern Israel.

After a visit to military headquarters, Netanyahu said he appreciated “the support of the American president,” but he said Israel would push ahead to return “calm and security” to Israeli citizens. He said he was “determined to continue this operation until its aim is met.”

He spoke shortly after President Joe Biden told Netanyahu that he expected “a significant deescalation today on the path to a cease-fire,” the White House said.

Biden had previously avoided pressing Israel more directly and publicly for a cease-fire with Gaza’s Hamas militant rulers. But pressure has been building for Biden to intervene more forcefully as other diplomatic efforts gather strength.

Egyptian negotiators have also been working to halt the fighting, and an Egyptian diplomat said top officials were waiting for Israel’s response to a cease-fire offer. The diplomat spoke on condition of anonymity in line with regulations.

Meanwhile, German Foreign Minister Heiko Maas said he would fly to the region Thursday for talks with Israelis and Palestinians.

Israel’s Foreign Ministry said the foreign ministers of Slovakia and the Czech Republic would also arrive in Israel Thursday, and that the diplomats were invited by Foreign Minister Gabi Ashkenazi “to express their solidarity and support” for Israel.

Earlier in the day, the Israeli military said it was widening its strikes on militant targets in southern Gaza to blunt continuing rocket fire from Hamas. At least nine people were killed Wednesday in the Gaza Strip. The round of fighting between Israel and Hamas began May 10, when the militant group fired long-range rockets toward Jerusalem after days of clashes between Palestinian protesters and Israeli police at the Al-Aqsa Mosque compound, a flashpoint site sacred to Jews and Muslims.

Heavy-handed police tactics at the compound and the threatened eviction of dozens of Palestinian families by Jewish settlers had inflamed tensions.

At least 227 Palestinians have been killed, and 1,620 people have been wounded.

Palestinians inspect the damage of a destroyed house Wednesday that was hit by an Israeli airstrike in town of Khan Younis, southern Gaza Strip.

the associated press