"Among the agreed provisions is one stating the deal would not expire even if Greenland became an independent country in the future.

The official added that under the deal, the US has unilateral power to build additional military structures with no approval needed from Greenland or Denmark. It includes "permanent access, basing and overflights rights," the official said.

It also bans non-Nato countries from building bases in Greenland, and "bans adversaries from making investments in Greenland that could threaten the United States".

The official added that under the current status quo, adversaries have been allowed to invest in Greenland's "sensitive sectors without investment screening".

The official specifically referenced Russia and China, saying it blocks them from deploying troops or making investments in "sensitive sectors".

Without the official text being released, it is unclear how exactly the deal differs from a 1951 agreement with Denmark, under which the US can send as many troops as it wants to Greenland."

https://www.bbc.com/news/articles/c63d7lexyym1o

They already had these sorts of things (and Denmark, as a NATO member, was already pretty unlikely to permit Russian basing there).

https://avalon.law.yale.edu/20th_century/den001.asp

"United States aircraft may fly over and land in any territory in Greenland"

"the Government of the United States of America, without compensation to the Government of the Kingdom of Denmark, shall be entitled within such defense area and the air spaces and waters adjacent thereto... (ii) to construct, install, maintain, and operate facilities and equipment"

etc.