No, they are not US companies.
Using the top right example from the image (DUNS 126952720):
The "Ministry of Economy and Finance" does have an office in the United States at 4101 Reservoir Road NW, as claimed. The entity (which is not a company) has a DBA ('Doing Business As') identity, which is necessary to have a bank account - itself necessary for things like efficient payroll for employees. That DBA is, tellingly, "French Trade Commission."
The listed website is www.franceintheus.org, the same and top result for when you Google for "French Embassy Website."
As a matter of law, the French Embassy is required to have a legal identity in the United States in order to have operating accounts, sign leases/own property, operate vehicles, and so forth. They also hire US citizens to do work for them, which requires an EIN for income tax purposes, etc.
The existence of these do NOT mean the French Embassy is a corporation of the United States. They are merely concessions made to the need for smooth operations, transparency, and auditability.
As noted in comments, DUNS numbers are trivially easy to acquire and are also for the purposes of transparency, ease of operations, etc. They allow anyone who wishes to contract with the DUNS registrant to have a measure of confidence in the identity and reputation thereof.
The "Edit Details" link in each of the example registrations reveals the source to be a private business directory (I'm not able to positively identify which one) - which is not an official public records repository by any means. Typically these are for-profit services that are ad-revenue and member-fee funded.
A search of the Washington DC business records (login required, but free to register) - which would contain the registration for any lawfully organized company has no record of either of the putative 'corporations' with Washington DC Addresses (see note below). The original source has grossly misread the information and proceeds from a lack of knowledge of business law.
Note: Search terms were "French" "France" "Ministry" "Economy" (not particularly helpful) and "Finance" (also not particularly helpful by itself).
Business registrations are matters of public record in the United States. In Washington, DC particularly businesses must be registered unless they are Sole Proprietorships. These registrations are available to the public as a matter of consumer protection. Businesses with headquarters elsewhere are required to submit Foreign Registration Statements.
Tools to search these records are routinely provided by governments who require such registrations (in this case the relevant entity is the District of Columbia).
