 North Korea warns Washington it made down U.S. warplanes in its airspace. North Korea has sent a warning to the United States that it made down U.S. reconnaissance planes in its airspace, according to a spokesman for the North Korea's Ministry of National Defence. The U.S. will surely have to pay a dear price for its provocative air espionage, frantically staged even invading the opposite side's airspace without previous notice. There is no guarantee that such a shocking accident as downing the U.S. Air Force strategic reconnaissance plane will not happen in the East Sea of Korea. KCNA news agency quoted him as saying in a statement, the North Korean military official pointed to the U.S. strategic reconnaissance planes, RC-135, U-2S and reconnaissance drone RQ-4B, flying in North Korea's airspace in turn for eight straight days from July the 2nd to the 9th. We are now maintaining our utmost patience and self-control, but everything has its limits. The present is the time when the U.S. is near the critical point to be concerned, he added. In April, the presidents of the Republic of Korea and the United States, Yun Suk-yul and Joe Biden, approved a declaration under which South Korea affirmed its commitment to nuclear non-proliferation while the U.S. pledged to provide information on strategic and nuclear planning. Additionally, Washington vowed to step up the deployment of its strategic arms on the Korean peninsula, including nuclear submarines.