WASHINGTON (NEXSTAR) -- President Joe Biden, as he left Germany, says the U.S.  will restart ceasefire and hostage release negotiations, after the Israeli military killed Hamas' leader, Yahya Sinwar.  "We think there's a road to peace there," Biden said. Defense Secretary Lloyd Austin, at a meeting with the U.S European allies, says Sinwar's death is a major achievement and an opportunity for progress. "To achieve a lasting ceasefire, to end this awful war and to rush humanitarian aid into Gaza," Austin said. White House National Security Spokesperson John Kirby says Sinwar was the main obstacle to a ceasefire agreement, and the U.S. can resume ceasefire negotiations where it left off. "He would just, he would just refute it and, and not and refused to move forward," Kirby said. "Hopefully, we can get that restarted with him now no longer in the position he was to, to block it." U.S officials say Hamas is now severely weakened and Sinwar's death limits its ability to operate and act. "Hamas is in a much, much, much weakened position than it ever was before," Kirby said. Kirby says it's too soon to tell how Hamas will proceed. "Who they might anoint as Sinwar's successor and what that individual, may be willing to pursue, one way or the other, for good or for ill, it's just too soon for us to know," Kirby said. However, Israeli Prime Minister Benjamin Netanyahu said even though the war in Gaza is not over, this is the beginning of the end. In response, Hezbollah says its war with Israel is entering a new phase with Sinwar's death.