For the first time this year, a Chinese fighter jet has been spotted on the runway of an artificial island created by China in the South China Sea.

The Asia Maritime Transparency Initiative (AMTI), which is part of the larger think-tank, Washington’s Center for Strategic and International Studies, reports that a Chinese J-11 fighter was visible on the runway of one of the artificial islands China has produced to extend their claim over the heavily traversed waterway in satellite images taken on March 29th.

This new deployment comes only days before China’s President Xi Jinping arrived in the United States to meet with President Donald Trump at his Mar-a-Lago retreat in Florida.  The much-anticipated summit is expected to be a fairly contentious one, as President Trump and key members of his staff have been quite critical of Chinese trade practices and their continued effort to assert their will over the South China Sea.

“This isn’t a first, but it’s the first time in a year,” AMTI director Greg Poling said of the fighter deployment. “There are likely more [fighters] in the hangars nearby.”

Although this isn’t the first time a fighter jet has been spotted on China’s artificial islands, it could mean the beginning of longer term deployments to facilities that have recently completed construction.  Despite the presence of fighter jets, and facilities that appear to be intended to house surface to air missiles and other weapons platforms, China has repeatedly denied allegations that they are attempting to militarize the waterway responsible for an estimated one-third of global commerce, claiming instead that they are merely defensive measures being taken to maintain and defend “freedom of navigation” throughout the region.

Philippine president Rodrigo Duterte also recently ordered his nation’s military to move toward populating uninhabited islands in the South China Sea – a move that will likely be seen as a clear break from previous statements he’s made in support of China’s policy in the region.

“It’s like we’re all competing to take these islands. And what’s ours now at least, let’s take it and make a strong point there that this is ours.  (We) must build bunkers or houses there and make provisions for habitation.” Duterte said of the Philippine controlled islands in the South China Sea.

The United States currently estimates that China has created around 3,200 acres worth of buildable land across seven different islands in recent years, many of which have already been equipped with military structures and runways designed for fighter jets such as the J-11 spotted in late March.