(CNN) China says it has landed long-range bombers for the first time on an island in the South China Sea, the latest in a series of maneuvers putting Beijing at odds with its neighbors and Washington over China's growing military presence around disputed islands.

The People's Liberation Army Air Force (PLAAF) announced on Friday it successfully organized the takeoff and landing of several bombers, including the nuclear-capable H-6K, on an unspecified island. The PLA claimed the mission was a part of China's aim to achieve a broader regional reach, quicker mobilization, and greater strike capabilities.

"The islands in the South China Sea are China's territory," Chinese Foreign Ministry spokesperson Lu Kang said in a statement Monday. "The relevant military activities are normal trainings and other parties shouldn't over-interpret them.

"As for the so-called militarization mentioned by the US, what we do is fundamentally different from the US sending its military aircraft and warships from thousands of miles away to this region and posing a threat to other countries."

A military expert, Wang Mingliang, was quoted in the statement as saying the training will hone the Chinese air force's war-preparation skills and its ability to respond to various security threats in the region, where China claims large swathes of territory.

The South China Sea is one of the most contested regions in the world, with overlapping territorial claims by multiple countries including the Philippines, Malaysia, Brunei and Vietnam.

Over the past few years China has been rapidly transforming various reefs and inlets into artificial islands to install military infrastructure. Some experts have called them "unsinkable aircraft carriers."

A Twitter post by the Chinese Communist Party's official newspaper, People's Daily, shows video of a long-range bomber taking off, flying, and landing on one of the islands. Analysts at the Center for Strategic and International Studies' Asia Maritime Transparency Initiative (AMTI) said it was thought to be Woody Island, China's largest base in the Paracel Islands and the only one with an airstrip long enough to allow bomber landings.

Chinese bombers including the H-6K conduct takeoff and landing training on an island reef at a southern sea area pic.twitter.com/ASY9tGhfAU — People's Daily,China (@PDChina) May 18, 2018

The move is a strategic accomplishment for China to further reinforce its military and political power in the disputed waters.

Upgrading capabilities

The H-6K is a considerable upgrade from the fighter jets believed to have previously landed on the islands. China's top-of-the-line bomber is capable of reaching a nearly 1,900-nautical-mile (3,500-kilometer) radius. Flying the twin-engine bombers out of Woody Island would mean the entirety of Southeast Asia is within combat flight range, experts say.

"The H-6K is significant because it provides Beijing with longer-ranging bomber capabilities that can drop precision-guided munitions on both ground and sea targets," Rand Corp. defense analyst Derek Grossman said in an email to CNN.

"Moreover, landing the bomber on Woody Island provides an opportunity for Chinese pilots to train under realistic circumstances," Grossman said.

While Woody Island sits in the central South China Sea, the AMTI says satellite imagery indicates China has built near identical operational runways at its three main outposts in the Spratly Islands known as Mischief, Subi and Fiery Cross Reef, which sit near the southern extent of the sea.

China for the first time landed bomber aircraft, including H-6Ks, on Woody Island in the #SouthChinaSea. AMTI shows the bombers' range, why it matters, and the likelihood of more showing up on the Spratlys https://t.co/doqM4stwZE pic.twitter.com/bl0IUdNOiu — AMTI (@AsiaMTI) May 20, 2018

Should Beijing soon pursue deployments from the Spratlys, as predicted, they could potentially reach northern Australia and US defense facilities on Guam, according to the AMTI.

Military activities

This comes just weeks after reports that the Chinese military installed radar jamming equipment and deployed their first missiles in their Spratly holdings.

And in mid-April, China conducted its largest-ever naval parade in the South China Sea, which came after the aircraft carrier Liaoning led a flotilla of 48 naval vessels plus 76 fighter jets in two-days of combat drills.

In a 2015 visit to Washington, Chinese President Xi Jinping assured then-US President Barack Obama, "China does not intend to pursue militarization." But US military officials say China's recent military activities belie that promise.

Pentagon spokesman Lt. Col. Christopher Logan told CNN, "the United States remains committed to a free and open Indo-Pacific," he adds, "China's continued militarization of disputed features in the South China Sea only serves to raise tensions and destabilize the region."

At the US Navy Pacific Fleet's change of command ceremony in Hawaii on Friday, outgoing commander Adm. Scott Swift called what is happening in the South China Sea an example of "using might to make it right ... a creeping genesis of a new rules-based order formed on the basis of military power, not international consensus."

Earlier this month, the Trump administration warned China's growing militarization would provoke "near-term and long-term consequences," according to White House press secretary Sarah Sanders.

But experts, and one key US military commander, say China has put itself in a very strong position in the South China Sea.

While the US Navy regularly conducts freedom of navigation operations through the area, the PLA's maneuvers and deployments there suggest the operations have done little to slow the process.

"The Chinese don't fear they are provoking a crisis," said Bonnie Glaser, the director of the China Power Project at Center for Strategic and International Studies in Washington. "China has many more tools that it can use against its neighbors in peacetime and the US doesn't have sufficient capability to shape events."

"China has advantages in the "gray zone," she said. "As long as China builds up its military forces, but doesn't employ those forces, the US is not likely to use military force."

US Adm. Phillip Davidson, nominated to head the US Pacific Command, told the Senate Armed Services Committee during his confirmation last month, "China is now capable of controlling the South China Sea in all scenarios short of war with the United States."

'Small steps' in a larger plan

Experts say Beijing has no intention of backing off any time soon.

"South China Sea exercises are inevitable, though the precise timing may depend on the extent to which Beijing assesses that it needs to deter counter-claimant activities and freedom of navigation operations by the US and its allies," Grossman said.

Exercises around the South China Sea islands are "small steps that incrementally change the status quo in China's favor without provoking a military response from the United States," said Glaser.

But they still give Washington plenty to worry about.

"We know they have runways, they have cannons, they have — everything in there is military. And it's really pretty scary," Republican US Sen. James Inhofe said at Adm. Davidson's confirmation hearing.