North Korean Foreign Minister Choe Son-hui has vowed efforts to strengthen diplomatic exchanges and cooperation with China in her congratulatory message to China's top diplomat, Wang Yi, on China's key anniversary, state media reported Thursday. Choe's message was delivered to celebrate the 76th anniversary of China's founding the previous day, according to the Korean Central News Agency (KCNA). North Korea "will make joint efforts to further develop its cooperative relations with China and strengthen bilateral exchange and cooperation in the diplomatic field," read the message, carried by the KCNA. Choe returned home Tuesday after making a four-day trip to China. North Korean leader Kim Jong-un traveled to Beijing last month to attend China's military parade.