New structure seen at missile equipment production site in North Korea

A new structure was spotted in a satellite image of a factory where North Korea makes military equipment used in the launch of long-range missiles. The image, which was taken on December 19, shows the March 16 Factory near Pyongyang where North Korea manufactures trucks used as mobile launchers for its long-range missiles. The new structure appears to be an expansion of the factory.

The images come just ahead of the deadline set by North Korea for the United States demanding concessions over tariffs. The US speculates that North Korea will do something aggressive by launching a missile or plan something offensive despite opposition.

Ahead of year-end, North Korea had warned that it might just have a "Christmas gift" for the US and the nature of the gift will depend on the US' actions. Nuclear talks between the two states have been stalled since the February summit between leaders Donald Trump and Kim Jong-un fell apart.

Read: North Korea's Kim Discusses Military Capability As US Deadline Approaches

Surveillance is part of US defence

Planet Labs, an American private Earth-imaging company based in San Francisco, also released several other images of the site showing before and after images of the December 7 test, which is one of the two missile tests reportedly conducted by North Korea.

The rare release of the photos by the US Defense Visual Information Distribution Service shows the Asian country's intent. The service is operated by an arm of the US Department of Defense, cites reports. It was shared by Jeffrey Lewis, director of the East Asia non-proliferation program at the Middlebury Institute. 

Read: South Korea To China: Stalled US-North Korea Talks Harmful For Pyongyang

South Korea-US Defence drills

On the other hand, South Korean and US special forces troops recently conducted drills simulating the infiltration of an enemy facility. The commandos reportedly raided the facility and led out a man with his hands tied behind the back during the exercise -- described as a joint regular close-quarters battle training last month at a US military base -- in the southwestern South Korean city of Gunsan.

The drill was designed as a hostage rescue operation training as part of a counter-terrorism drill conducted quarterly by the allies, said a South Korean official to the media. A local newspaper claimed that the drills were intended to simulate a scenario to capture North Korean executives.

Read: Trump And Abe Hold Telephonic Conversations, Discuss North Korea Amid Tensions

Read: North Korea Says US Could 'pay Dearly' Over Human Rights Criticism

(With inputs from Associated Press)