Israel vowed to completely destroy Islamist group Hamas on the eve of US Secretary of State Antony Blinken's expected visit Thursday as Washington underscores support for the Jewish state in a war that has seen the death toll spiral into the thousands. In Gaza, officials have reported more than 1,200 people killed in Israel's uninterrupted campaign of air and artillery strikes, while the UN said more than 338,000 people have been displaced.