The posters and defiant slogans were unveiled this past week, the latest sign that tensions remain high between Washington and Pyongyang over the North’s nuclear ambitions and the sanctions imposed by other nations.

Political posters have long been an important feature of culture and daily life in the North. They are everywhere: on the walls of public buildings, at the gates of schools and at factories and collective farms. They are used to instill in North Koreans the tenets of party ideology and loyalty.

The KCNA state news agency did not explain why these themes were chosen this time. But the posters were unveiled after President Trump recently warned North Korea that it would face “fire and fury” from an American military that was “locked and loaded” if the country made any nuclear provocations.

The North, in turn, threatened to launch four intermediate-range ballistic missiles into the waters near Guam, an American territory in the Western Pacific, to teach Mr. Trump a lesson.