The Democratic People's Republic of Korea soldiers salute bronze statues (not pictured) of DPRK's late founder Kim Il-sung and late leader Kim Jong Il at Mansudae in Pyongyang, in this photo released by Kyodo April 25, 2017, to mark the 85th anniversary of the founding of the Korean People's Army. [Photo/Kyodo via REUTERS]

Pyongyang marked a key military anniversary on Tuesday with a major artillery drill after Seoul announced joint naval exercises with a US aircraft carrier group this weekend.

Speculation has been mounting that Pyongyang would carry out a sixth nuclear test or another missile launch on Tuesday to mark 85 years since the founding of its army.

The Republic of Korea's Yonhap News Agency cited an unnamed government source as saying the Democratic People's Republic of Korea marked the anniversary with its "largest ever live artillery drill", carried out in the eastern port city of Wonsan and presumed to have been overseen by leader Kim Jong-un.

US President Donald Trump said on Monday that the United Nations Security Council must be ready to impose tougher sanctions on the DPRK over its nuclear and missile programs, calling the status quo "unacceptable".

"This is a real threat to the world," Trump said while hosting UN Security Council ambassadors at the White House.

On Friday, the Security Council will have a special ministerial meeting on the Korean Peninsula nuclear issue.

Washington has sent the nuclear powered aircraft carrier USS Carl Vinson and its carrier group to the Korean Peninsula, where it is expected to arrive later this week.

The vessel will take part in ongoing joint naval drills with ROK forces, the ROK Navy said in a statement.

Foreign Ministry spokesman Geng Shuang said on Tuesday that those who are disappointed that a sixth nuclear test was not carried out in the DPRK "are anxious to see the world in disorder".

"We urge all related parties to keep calm and restrained, and not to take actions that intensify the tension," he said at a daily news conference in Beijing.

According to Geng, China and the DPRK are in contact and the diplomatic channels between the two countries are "very smooth".

He also said China has been making efforts to solve the peninsula's nuclear issue in an appropriate and effective way, as both a regional country and a responsible member of the international community.

Wu Dawei, China's special representative on Korean Peninsula affairs, arrived in Japan on Tuesday to exchange views over the current Korean Peninsula issue.

"We hope related parties, including Japan, can work with China to push for an early and peaceful resolution of the issue, make due efforts, play its due role and shoulder due responsibilities," he added.

AFP contributed to this story.