ISTANBUL Chinese President Xi Jinping extended his congratulations Tuesday to North Korean leader Kim Jong Un over the 77th anniversary of the founding of the Democratic People’s Republic of Korea (DPRK). Xi said Beijing stands ready to “enhance strategic communication, maintain close exchanges and cooperation with the DPRK and join hands to promote China-DPRK friendship,” the state-run Xinhua News Agency reported. Xi pointed out the “socialist cause” of the two countries and called on both