In North Korea there are increasing signs of a renewed push for nuclear armament.

According to experts, satellite images show construction work for the first time since the Punggye-ri nuclear test site closed in 2018.

The pictures taken on Friday show the construction of one building and the repair of another building.

Experts at the James Martin Center for Nonproliferation Studies in the United States pointed out that the test site was many months, if not years, away from being used for new atomic bomb tests.

The American secret service is also assuming new nuclear efforts and expects major tests this year.

North Korea had tested a record number of missiles in January, including the largest since 2017. International observers also reported that the nuclear power plant in Yongbyon is in full operation and may be producing uranium for nuclear bombs.

North Korea refuses inspectors entry

The American secret service suspects that the rocket launches at the beginning of the year could be the prelude to an intensified development of ICBMs and atomic bomb tests this year.

The US Directorate of National Intelligence report said North Korean leader Kim Jong Un may remain determined to expand its nuclear arsenal.

Punggye-ri has been shut down since North Korea announced a self-imposed moratorium on nuclear weapons tests in 2018.

However, Kim has stated that he no longer feels bound by this moratorium as negotiations with the US to abandon nuclear weapons stalled in 2019.

In 2018, North Korea invited foreign media to observe a blast in Punggye-ri.

However, the communist country refused entry to international inspectors.

It was then speculated that the facilities could be rebuilt.

Punggye-ri is North Korea's only known nuclear test site.

From 2006 to 2017, North Korea conducted six underground nuclear weapons tests there.

North Korea said last week that the latest missile test was aimed at developing reconnaissance satellites.

The United States, South Korea and Japan fear North Korea wants to develop ballistic missiles.

This is forbidden to North Korea by UN Security Council resolutions.