BBC英语,急急急急,英语翻译, 尽快采纳,万分感激

题目

BBC英语,急急急急,英语翻译, 尽快采纳,万分感激
He also said the United States believes it likely killed al-Harithi in an airstrike in southern Yemen in recent days. But he cautioned its "very difficult" to confirm the killing.这个句子中 believes it likely在句子中是不是美国相信有可能...he cautioned its "very difficult" to confirm the killing是不是他警告它的很困难去确认那个死亡,我翻译的很别扭,球高手指点一下啊,万分感激啊,谢谢啊
请高手帮助我翻译一下啊，最好能够分析一下句子结构啊，谢谢啊

答案

他还说,美国认为在最近几天也门南部的一次空袭中可能已经***了al-Harithi.但是他提醒说,确认死亡是很困难的.
believe it likely 是believe that it likely 省略了that从句