U.S. officials concerned about North Korea 's 'ratcheting up of rhetoric ' Tensions have been rising for months . NEW : Beijing is ` ` likely to try to calm us down , '' China 's foreign ministry says . South Korea ` ` seriously '' China 's threat to jeopardize joint exclusive economic zone . The Pentagon says North Korean threats follow a familiar pattern . North Korea threatens ` ` all - out nuclear and nuclear war '' on its enemies , state news reports .
NEW : Beijing is ` ` likely to try to calm us down , '' China 's foreign ministry says . South Korea ` ` seriously '' China 's threat to jeopardize joint exclusive economic zone . The Pentagon says North Korean threats follow a familiar pattern . North Korea threatens ` ` all - out nuclear and nuclear war '' on its enemies , state news reports .