North Korea accused the United States on Sunday of stepping up preparations to attack the communist state, a day after it delayed high-level talks with South Korea over Seoul's planned military drills with the US. North Korea's Minju Joson newspaper cited a reported US plan to deploy more submarines and reconnaissance aircraft to Asia-Pacific, as well as joint military exercises with Japan and planned drills with South Korea as evidence Washington was preparing to invade. "The US strengthening military moves on and around the Korean Peninsula is nothing but a premeditated maneuver to realize its hostile policy aimed at militarily stifling our republic," the newspaper said in a commentary carried by the North's official Korean Central News Agency. "Under the current tense situation, the nuclear deterrent force of our republic effectively contributes to guaranteeing peace and safety of our republic. ... (We) will make every effort to solidify our self-defense force," it said.