NAYPYITAW - US Secretary of State John Kerry said on Sunday Afghan Taliban leader Mullah Akhtar Mansour posed a 'continuing imminent threat' to US personnel in Afghanistan and to Afghans, and was a threat to peace. US officials in Washington said on Saturday US missile-firing drones had attacked Mansour and probably killed him in a strike in southwest Pakistan, near the Afghan border, authorized by US President Barack Obama. 'Yesterday, the United States conducted a precision air strike that targeted Taliban leader Mullah Mansour in a remote area of the Afghanistan-Pakistan border. Mansour posed a continuing, imminent threat' to US personnel and Afghans, Kerry told a news conference in the Myanmar capital. 'This action sends a clear message to the world that we will continue to stand with our Afghan partners as they work to build a more stable, united, secure and prosperous Afghanistan.'