North Korea has carried out another test of a rocket engine, the latest in a series of engine and missile tests this year. <br/><br/>A U.S. official told Reuters yesterday that the test could be part of its programme to develop an intercontinental ballistic missile. <br/><br/>The disclosure of the engine test came a day after the United States pressed China to exert more economic and diplomatic pressure on North Korea to help rein in its nuclear and missile programs. <br/><br/>U.S. President Donald Trump has warned that a major conflict with North Korea is possible over its weapons programs, though U.S. officials say tougher sanctions, not military force, are the preferred option.