The United States condemned North Korea's launch of four ballistic missiles, vowing that Washington was ready to "use the full range of capabilities at our disposal against this growing threat." "The United States strongly condemns the DPRK's ballistic missile launches tonight, which violate UN Security Council Resolutions explicitly prohibiting North Korea's launches using ballistic missile technology," the State Department's acting spokesman Mark Toner said in a statement. Toner added: "We remain prepared -- and will continue to take steps to increase our readiness -- to defend ourselves and our allies from attack, and are prepared to use the full range of capabilities at our disposal against this growing threat." Pyongyang launched four ballistic missiles on Monday in its latest challenge to US President Donald Trump, with three landing provocatively close to America's ally Japan. Seoul and Washington began annual joint military exercises last week that always infuriate Pyongyang, with the North's military warning of "merciless nuclear counter-action.