It was unclear exactly when the conversation took place on Sunday, but Xinhua's report of the call came out after a failed missile launch by North Korea.
Despite the mounting tensions, there has been little sign of strain on the streets of Pyongyang in recent days, where the focus has been on preparations for Saturday's anniversary.
The North regularly launches short-range missiles, but is also developing mid-range and long-range missiles meant to target USA troops in Asia and, eventually, the US mainland.
With the men wearing pins adorned with photos of Kim Il Sung, and the women in brightly coloured traditional dress, crowds lined up to bow to portraits of their state founder before touring an exhibition of photos and North Korean paintings.
Pyongyang has undertaken five nuclear tests since 2006. The event was held after North Korea's latest missile test prompted the U.S.to send an aircraft carrier to the region.
Satellite imagery analysis has noted activity at the North's main nuclear test site ahead of Saturday's 105th anniversary of the birth of the country's founder leader Kim Il-Sung.
Other senior officials joining Kim at the podium included Kim Won Hong, who the South Korean government had said earlier this year was sacked from his job as state security minister, presumably over corruption.
U.S. Vice President Mike Pence says North Korea's "provocation" is another reminder of the risks that U.S. and South Korean service members face every day "in the defense of the freedom of the people of South Korea and the defense of America in this part of the world".
Weapons analysts said there also appeared to be two new types of intercontinental ballistic missiles in canister launchers, but it remains unclear whether they have been tested.
The North has said it has developed and would launch a missile that can strike the mainland United States, but officials and experts believe such a threat is some time away.
Soldiers and marching bands filled the square, next to the Taedonggang River that flows through Pyongyang, followed by tanks, multiple-launch rocket systems and other weapons.
Earlier Friday, North Korea's Vice Minister Han Song Ryol told The Associated Press in an exclusive interview that his country will keep building up its nuclear arsenal in "quality and quantity" and said Pyongyang is ready to go to war if that's what President Donald Trump wants.
Last year North Korea, which regularly fires off short-range rockets, launched a long-range missile and carried out two nuclear tests.
North Korean soldiers also rolled out another large rocket that appeared to be the size of an ICBM, but what a South Korean military analyst said hasn't been seen before.
The new long-range weapon - the KN14 - was the centrepiece of an array of weaponry put on show at a military parade in the North Korean capital.
(AP Photo/Wong Maye-E). North Korean schoolgirls perform at the Mangyongdae Children's Palace on Friday, April 14, 2017, in Pyongyang, North Korea.
"If they attempt a full-scale war, we will respond with a full-scale war", Choe Ryong Hae, a senior official in the ruling Workers' Party and a key aide to Kim, said in a speech before the parade, the Times reported.
North Korea conducted two nuclear tests a year ago alone, advancing its goal to make nuclear weapons small enough to fit on long-range missiles.
U.S. Pacific Command said the ballistic missile, of a kind not yet determined, was launched from near a submarine base at Sinpo, a port city on North Korea's east coast.
The reclusive state has always been on a quest to develop a long-range missile capable of hitting the U.S. mainland with a nuclear warhead, and has so far staged five atomic tests, two of them previous year.