PYONGYANG, North Korea — Elaborate floral displays featured mini replicas of red-tipped missiles and long-range rockets at an exhibition that opened Friday in Pyongyang, underlining North Korean pride in an illicit arsenal that has put the region on edge.

North Korea has warned that it has weapons “on standby” and aimed at its foes if provoked, though it has not revealed specific plans to fire a missile or carry out another nuclear test.

However, as Secretary of State John Kerry arrived in Seoul on Friday for talks with South Korean officials, a senior U.S military official told reporters there was no sign of military movements backing up the threat. He spoke on condition of anonymity, saying he wasn’t authorized to speak publicly about military intelligence.

For weeks, North Korea has issued a torrent of war cries seen outside Pyongyang as an effort to raise fears and pressure Seoul and Washington into changing their North Korea policies, and to show the North Korean people that their young leader is strong enough to stand up to powerful foes.

U.S. and South Korean troops have been conducting annual joint military drills in the South since early March, including bringing out nuclear-capable stealth bombers and fighter jets in what the Air Force acknowledged was a deliberate show of force.

The escalation of tensions comes as North Korea is celebrating a slew of first anniversaries for its young leader, Kim Jong Un, who took power in December 2011 following the death of his father, longtime leader Kim Jong Il. He was named head of the Workers’ Party a year ago Thursday, and will mark his first year as head of the National Defense Commission, the top government body, on Saturday.

North Koreans also have begun celebrating the April 15 birthday of Kim’s grandfather, Kim Il Sung. The birthday is considered the most important of national holidays designed to cement loyalty to the ruling Kim family.

At Mansu Hill, where massive bronze statues of the two late leaders overlook the city, Pyongyang citizens were busy Friday morning scrubbing the steps up to the plaza with soap and water to prepare for the stream of people who will be paying their respects to the Kims.

At Kim Il Sung Stadium, schoolchildren being inducted into the Korean Children’s Union, a political organization for young North Koreans, pledged to study hard and to build up strength to defend their nation. Retired military officers helped them tie on red scarves to complete the ritual.

Loyalty to the Kims and to the state are drummed into North Koreans from an early age in this highly patriotic, militarized country, where banners along roadsides read “Defend to the death” and call on citizens to become “human bombs” for leader Kim Jong Un.

Though few North Koreans have access to international media, and instead get their news from state media, they said they were aware of the tensions with the U.S.

“The U.S is our sworn enemy,” said Ri So Hyang, a 13-year-old taking part in the Children’s Union ceremony. She said her brother had just enlisted. “I hope he’ll fight well against the U.S. imperialists since I cannot.”

At the flower exhibition, which featured massive displays incorporating the orchid named after Kim Il Sung, a guide called the current political situation “complicated.” Photo backdrops and mock replicas featured an array of missiles — including models believed to be medium-range and intercontinental ballistic missiles.

“I don’t know whether there will be a missile launch test, but if we do I think it will be just for national defense,” Kim Jong Gum said. “And I think there’s no need for other countries to try to tell us what to do and what not to do.”

No military parade or mass events are expected, but North Korea has used major holidays to show off its military power. Analysts say Pyongyang could well mark the occasion with a provocative missile launch, although it has not explicitly said it would conduct one.

During last year’s celebrations, North Korea failed in an attempt to send a satellite into space aboard a long-range rocket. The U.S. and its allies criticized the launch as a covert test of ballistic missile technology in defiance of a UN ban on the country’s missile and nuclear development.

Another try in December was successful, and that was followed by the country’s third underground nuclear test on Feb. 12, possibly taking the regime closer to mastering the technology for mounting an atomic weapon on a long-range missile.

On Thursday, the Committee for the Peaceful Reunification of the Fatherland, a nonmilitary agency that deals with relations with South Korea, said the coordinates of targets have been “put into warheads.” It didn’t clarify, but the language suggested a missile.

Officials in Seoul and Washington say Pyongyang appears to be preparing to test-fire a medium-range missile designed to be capable of reaching Guam. Foreign experts have dubbed the missile the “Musudan” after the northeastern village where North Korea has a launch pad, and say it has a range of 3,500 kilometers (2,180 miles).

Newly revealed U.S. intelligence shows Washington believes North Korea may be capable of arming a ballistic missile with a nuclear warhead, the U.S. Defense Intelligence Agency concluded in an assessment revealed Thursday.

South Korea, however, does not believe Pyongyang has a nuclear device small enough to put on a missile, Defense Ministry spokesman Kim Min-seok said.

U.S. President Barack Obama demanded an end to the escalating war rhetoric. In his first public comments since North Korea warned of a nuclear war, Obama called it time for the isolated nation “to end the belligerent approach they have taken and to try to lower temperatures.”

“Nobody wants to see a conflict on the Korean Peninsula,” Obama said Thursday, speaking from the Oval Office alongside U.N. Secretary-General Ban Ki-moon.

He sent Kerry to Seoul to discuss how to get China to join the United States in putting pressure on Pyongyang, according to a senior U.S. official who was present at the meeting.

China backed North Korea with troops during the 1950-53 Korean War and has been a major economic pipeline for the impoverished country. With little arable land, North Korea has struggled to feed its people, with two-thirds of the population of 24 million grappling with chronic food shortages, according to the World Food Program.

“If anyone has real leverage over the North Koreans, it is China,” James Clapper, the U.S. director of national intelligence, told Congress on Thursday. “And the indications that we have are that China is itself rather frustrated with the behavior and the belligerent rhetoric of … Kim Jong Un.”

Since taking power, Kim has pledged to end the era of “belt-tightening” in North Korea by placing his focus on reviving the economy.

But he also has enshrined the drive to build nuclear weapons — dubbed “the nation’s treasure” here — as a key state goal, billed in Pyongyang as a necessary defense against what North Koreans see as a persistent U.S. nuclear threat. A new Ministry of Atomic Energy Industry will be created in line with the push, the state-run Korean Central News Agency reported Friday.

North Korea has decided to launch a “ministry of atomic industry” to advance its nuclear industry, increase the amount of nuclear material and improve its quality, the Korean Central News Agency said Friday.

KCNA said the decision by the Presidium of the Supreme People’s Assembly was announced Thursday.

North Korea has spent decades trying to perfect a multistage, long-range delivery means for a nuclear bomb aimed at threatening the U.S., analysts say.

Pyongyang has acknowledged attempts to launch satellites into space aboard long-range rockets in 1998, 2009 and twice in 2012. North Korea also regularly stages short-range missile tests, and in 2006 a long-range missile launch broke apart shortly after liftoff.

North Korea says its rocket launches are part of a peaceful space program. But the U.N., Washington and others call the launches veiled tests of technology that can be used in ballistic missiles.