A satellite image by a U.S. company on Tuesday showed increased activity at North Korea's launch site used to fire off long-range missiles amid wide speculation over the North's looming missile test.

The image taken on Nov. 23 and released by DigitalGlobe shows "a marked increase in activity at North Korea's Sohae Satellite Launch Station," the U.S. imagery provider said, referring to the North's west coast launch site, often used to send off long-range missiles. The launching site, also known as the Tongchang-ri launch station, was used when the country launched in April what it called a satellite, which was believed by foreign countries to be a long-range missile.

DigitalGlobe said the recent activity is similar to launch preparations witnessed before the North's botched April 13 launch.

"Given the observed level of activity noted of a new tent, trucks, people and numerous portable fuel tanks... it could possibly conduct its fifth satellite launch event during the next three weeks, DigitalGlobe said.

DigitalGlobe's analysis is in line with South Korea's announcement last week that the North appears to be preparing to launch a new long-range missile at the west-coast launching site.

Responding to a report by Japan's Asahi Shimbun that U.S. satellites detected possible preparations by the North to test a long-range ballistic missile at the Dongchang-ri base, a senior government official said on Nov. 23, "We are judging that (North Korea) will launch a missile and are closely watching the situation."

According to the Japanese paper, U.S. satellites recently detected images of cargo believed to be missile parts similar to those shown in the April launch, and Pyongyang could be technically ready to fire off a missile as early as this month.

Pyongyang unsuccessfully launched a rocket in April, which was widely seen by other nations as a disguised attempt for a long-range missile test.

North Korea has repeatedly expressed its willingness to continue to launch "working satellites," claiming its independent right to use space. (Yonhap News)