Workers also carried red banners emblazoned with slogans praising their leaders and the country's strength as President Trump continued to tout military action "if Kim Jong-un utters one overt threat against the US".
"It's tailor-made for somebody to misuse", he added.
On Thursday, Kim Jong-un threatened to strike waters around the United States base in Guam.
Since the Clinton administration in the early 1990s, the US has reacted to Pyongyang's "nuclear blackmail" with negotiated agreements that lead to aid and an easing of sanctions followed invariably by broken promises, a growing nuclear arsenal and more threats.
Supercoppa, Inzaghi: "Dovremo fare una partita coraggiosa ed essere squadra"
Il tecnico biancoceleste, infatti, dovrà fare a meno di Keita . "Siamo orgogliosi di essere qua, ce lo siamo meritati sul campo". Ringrazio i compagni, mister e società per l'opportunità di essere capitano . "Però non mi fermerò e giocherò come sempre".
The missiles are created to carry nuclear weapons but it is not clear if the North has warheads small enough to fit on them, or the technology to bring them back to earth in one piece.
Yun Sun, a senior associate at the Washington, D.C. -based Stimson Center, argued North Korea would not need intercontinental ballistic missiles to strike South Korea, whose capital sits just 35 miles from the border.
Britain's membership of NATO does not automatically oblige it to participate in a conflict between Trump's America and Kim's North Korea, even if the latter attacks U.S. military bases in the Pacific.
In the past week Donald Trump has retweeted his threats to rain down fire and fury, boasted about the readiness of his nuclear army and told a nation his "military solutions" were "fully in place, locked and loaded, should North Korea act unwisely".