Vietnam has expanded its island building in the South China Sea's disputed Spratly archipelago in the past year, adding 534 acres (216.1 hectares) of land, and has also begun to construct specialized infrastructure there, a U.S. think tank reported.

The report on Friday by the Asia Maritime Transparency Initiative at Washington's Center for Strategic and International Studies added the following details:

• The new dredging across the Spratlys brings the total area of artificial land reclaimed by Vietnam in the archipelago to about 2,771 acres.

• After finishing landfill operations at Barque Canada Reef, now Vietnam's largest base in the islands, in spring 2025, Hanoi began smaller expansions at several new features in the second half of 2025.

• The expansion has caused additional environmental damage.

• Vietnam's total reef destruction, including reefs covered by landfill and areas dredged to create channels and harbors, now stands at roughly 4,120 acres.

• Vietnam’s island-building activities in the Spratlys had appeared to be catching up to China's in early 2025, but new Chinese reclamation activities at Antelope Reef have widened the gap, with China’s totals now about 5,460 acres of artificial land, and 6,224 acres of reef destruction.

• Vietnam has made notable infrastructure developments on larger, more developed reefs, with an additional three harbors taking shape at Grierson Reef, Petley Reef, and South Reef.

• The new work brings the total number of harbors Vietnam has in the archipelago to 15, 11 of them created since 2021. Initial construction of another likely harbor can already be seen at Landsdowne Reef.

• Vietnam's Washington embassy did not immediately respond to request for comment. Last year, China said it opposes Vietnam's construction activities at Barque Canada Reef, calling it Chinese territory. China claims almost the entire South China Sea, despite overlapping claims by Brunei, Malaysia, the Philippines and Vietnam.

  -David Brunnstrom/Reuters