North Korea said Saturday it had successfully tested an engine designed for an inter-continental ballistic missile (ICBM) that would "guarantee" the ability to launch a nuclear strike on the US mainland, state media reported.

Now North Korea "can tip new type inter-continental ballistic rockets with more powerful nuclear warheads and keep any cesspool of evils in the earth including the US mainland within our striking range," leader Kim Jong-Un, who monitored the test, was quoted as saying.