Hong Kong (CNN) New satellite imagery of China's first overseas military base reveal it to be bigger and more secure than previously thought.

Two images provided by Stratfor Worldview and Allsource Analysis show the base in Djibouti, located at a strategic choke point on the Horn of Africa, to be heavily fortified with three layers of security and has about 23,000 square meters (about 250,000 square feet) of underground space, according to analysis provided by Stratfor.

"This type of construction is in line with known Chinese practices in hardening their military bases. The underground structures allow for unobserved activity, as well as offer protection to vehicles or facilities critical to the Chinese mission in Djibouti," Stratfor, a geopolitical intelligence firm, said in an analysis accompanying the images.

China dispatched troops to the base earlier this month . The United States, France and Japan also have permanent military bases there, but Tack said those are not as heavily fortified.

It's not clear how big the Chinese base is, but for comparison, the US base was expanded to 500 acres in 2007.

"Even though this is just one of those bases in Djibouti as several other countries have, China has taken its own methods into Djibouti," Stratfor Senior Analyst Sim Tack told CNN.

China's Defense Ministry has touted the base as a way for the People's Liberation Army to help bring peace and security to the region by providing a means of carrying out anti-piracy operations and humanitarian assistance.

However an image from July 4 showed the Chinese had not yet begun building docks, which Stratfor called notable due to the bases aforementioned purpose.

"I wouldn't say it's irregular, but I would've expected to see a dock," Tack said.

A dock will likely be constructed eventually, and China could use Djibouti's commercial port until that time, according to Stratfor.

Analysts say the base is part of China's efforts to establish a truly global naval force that's capable of conducting operations around the world -- a so-called "blue water navy" -- though Chinese state media has pushed back on suggestions that Beijing will flex its muscles globally.

"One of the big hall marks of a superpower is having blue-water capacity, and China is in the awkward position where it sees itself as a superpower, other countries perceive it as a superpower, but it doesn't actually have the full capacity of a superpower as yet," Yvonne Chiu, an assistant professor at the Department of Politics at the University of Hong Kong, recently told CNN.

But the base's construction also indicates that it will be used for more than naval purposes, according to the analysis.

It has tarmac and hangars appear large enough to house various types of helicopters, but not fixed-winged aircraft like drones or fighter jets. Those additions will allow the base to have aerial capabilities as well.