SEOUL, South Korea — Long columns of goose-stepping soldiers, accompanied by what North Korea claimed were nuclear-tipped missiles, marched through central Pyongyang, the capital, on Saturday, as the country’s leader, Kim Jong-un, gave his first public speech in three years to emphasize his “love for the people” and declare his readiness to “fight any form of war” with the United States.
Mr. Kim celebrated the 70th anniversary of his ruling Workers’ Party on Saturday with what appeared to be one of the largest military parades the North had ever organized. As warplanes flew overhead, the plaza in Pyongyang was filled with soldiers and citizens chanting slogans of loyalty to the Kim family and waving pink and red artificial flowers in synchronized moves.
In a 25-minute speech before the parade, Mr. Kim spoke of his “love” and “dedication to the people,” whom he thanked for staying with his party through decades of American-led economic sanctions and blockades.
In his first public speech, before a similar military parade in 2012, Mr. Kim promised that North Koreans would “never have to tighten their belt again.” Pyongyang, the showpiece capital where the people most loyal to the regime are allowed to live, has since gone through a major face-lift. But economic conditions for people in the rest of North Korea remain dire, according to international human rights groups.
Mr. Kim’s efforts to reinvigorate the economy are hampered by United Nations sanctions, prompted by the North’s nuclear and long-range missile programs. His government also spends lavishly to maintain the personality cult surrounding his family.
On Saturday, Mr. Kim did not mention his nuclear or missile programs but vowed to continue his policy of pursuing a nuclear arsenal and economic development simultaneously.
“Our revolutionary armed forces are ready to fight any form of war the American imperialists want,” he said, while the only prominent foreign guest — Liu Yunshan, a member of the Standing Committee of the Chinese Politburo — stood nearby.
Mr. Liu is the highest-ranking Chinese official to visit the North since Mr. Kim rose to power in late 2011. President Xi Jinping of China also sent a warm note to Mr. Kim, a sign that relations may be thawing after a deep chill.
In the message, widely reported by the Chinese state media, Mr. Xi said he not only extended the congratulations of the Chinese Communist Party but sent his own personal good wishes. He hailed Mr. Kim for having achieved “positive progress in developing the economy, improving livelihoods, and so on.”
China is the isolated North’s only major ally, and Mr. Xi had seemed to establish a new distance between the countries soon after taking power in late 2012. He said that no country should be allowed to destabilize the Asian region or the world for “selfish gain,” a statement that was interpreted as a criticism of Mr. Kim’s nuclear weapons program.
Despite its concerns about the North’s nuclear program, China has not used its full economic leverage to discourage the North from pursuing it, apparently being more concerned about potential instability in the North that could spill into its territory. China’s economic largess keeps North Korea’s bare-bones economy afloat, but a debate has been roiling in the past year among Chinese military officials and academics over whether its ally is more a liability than an asset. China has also been expanding its ties to South Korea.
A Chinese expert on North Korea, Yang Xiyu, said the tone of Mr. Xi’s letter to Mr. Kim was fairly standard.
The wording is “always the same no matter whether the bilateral relationship is in good shape or bad shape,” said Mr. Yang, a senior fellow at the China Institute of International Studies.
But John Delury, an associate professor of international studies at Yonsei University in Seoul, said Mr. Xi seemed to have used the occasion to mend fences with the North, at least to a degree.
“Xi’s letter marks the Chinese leader’s first real effort to make friends with Kim Jong-un,” Mr. Delury said. “The fulsome praise of the Kim dynasty is new for Xi, whose administration has sounded guarded, even irritated, in its language toward Pyongyang.”
Mr. Delury noted that Mr. Xi’s letter did not mention denuclearization, in contrast with an earlier message carried by Vice President Li Yuanchao, who in 2013 tried to press North Korea to slow down its nuclear program.
Mr. Xi’s failure to mention denuclearization will disappointthose in Washington who believed that Beijing was coming around to their hard-line stance toward Mr. Kim, Mr. Delury said.
The North’s state-run Korean Central Television showed columns of tanks, drones and rocket tubes. South Korean officials said that the tubes included a new model with a range long enough to strike South Korean and American military bases south of Seoul. The highlight was what South Korean officials said appeared to be a new version of KN-08 long-range missiles.
The KN-08 is widely believed to have been designed as the North’s first intercontinental ballistic missile. But it has never been flight-tested, so when it was first shown in public in 2012 and 2013, some outside analysts said it might be a mock-up of a system still under development.