Here is a list of countries that own land in the United States based on available data:

Canada: 31% of foreign-owned land, approximately 12.8 million acres.
Netherlands: 12% of foreign-owned land, around 4.6 million acres.
Italy: 7% of foreign-owned land.
United Kingdom: 6% of foreign-owned land.
Germany: 6% of foreign-owned land.
Portugal: 3.6% of foreign-owned land.
France: Also mentioned but specific percentages not provided.
Japan: Notable but specific percentage not detailed.
Sweden: Notable but specific percentage not detailed.
China: Over 1% of foreign-owned land, with approximately 500,000 acres by the end of 2022.

Additionally, there are over 100 other countries owning smaller portions of U.S. land, including:

India
Saudi Arabia
Iran