Tel Aviv, Dec 15 : A senior US official said that Hamas leader Yahya Sinwar's "days are numbered" and added that the latter had 'American blood on his hands'. The official made the remarks while addressing reporters here on Thursday night on US National Security Adviser (NSA) Jake Sullivan's meetings in Israel. Although Israeli leaders have voiced such threats against the terrorist leader, this is the first time that a senior US official has made a direct comment referring to Sinwar. 'I also think it's safe to say it doesn't matter how long it takes'justice will be served,' the senior US administration official said. At least 38 Americans were killed during the October 7 Hamas attack, and eight US citizens and permanent residents are among the roughly 135 currently being held hostage in Gaza. Earlier on Thursday, Sullivan met Israeli Prime Minister Benjamin Netanyahu and his War Cabinet members. Netanyahu thanked the NSA for Washington's support to Israel in its war against Hamas. The Prime Minister's Office in a statement said that Netanyahu and Sullivan discussed the continuation of the Israel-Hamas war until victory and the achievement of the common goals. They also spoke about the elimination of Hamas, release of all the hostages, dismantling of Hamas' military capabilities, and the end of its rule in Gaza. Discussions on continued humanitarian aid for civilians in Gaza and the threat of Hezbollah in Northern Israel were also held between them. Defence Minister Yoav Gallant, War Cabinet Minister Benny Gantz, IDF chief Herzi Halevi, Shas head Aryeh Deri, National Security Adviser Tzachi Hanegbi, Netanyahu's Chief of Staff Tzachi Braverman, Cabinet Secretary Yossi Fuchs, and Israel's ambassador to the US Mike Herzog were among those at the meeting. /IANS