What are US passport requirements to visit France

you need a passport. That is the requirement.

The only requirement is a passport that has at least 3 months validity on it after you leave France. The US State Dept recommends a 6 month validity and some airlines may adhere to this also so it's a good idea. The only other requirement is that you don't stay any longer than 90 days in France combined with any other Schengen zone country.

Yes and it has to be valid not expiring for the next three to six months

Mostly correct. The actual rules are here on the EU website: https://europa.eu/youreurope/citizens/travel/entry-exit/non-eu-nationals/index_en.htm
It is the EU that sets the rules, so that is the definitive answer. Some other websites (including the US government) get it wrong.

• Your US passport must be valid for 3 months after the date you intend to leave the Schengen Area.
  • The Schengen Area is a group of countries, including France, which have a common passport requirement for visitors.
  • Your passport will be checked (and possibly stamped) when you enter the Schengen Area, and when you leave, but not when travelling between Schengen countries.
• You need at least one blank (unused) page, for entry and exit stamps.
• You are allowed "90 days in any 180" in the Schengen Area.

Although the EU rules are the official ones, the traveler must first get past an airline employee at the departure airport. If that employee is confused and thinks the passport needs to be valid for 6 more months, the traveler equipped with a passport acceptable to the EU destination may not make it onto his or her flight.

In the near future, a passport alone for US citizens will not be sufficient for entry into the Schengen zone. An entry authorization will be required, it is not being called a visa, which is issued somewhere around 24 hours before your planned trip. I do not recall the exact start date.

This is what the US makes Schengen citizens do for US entry so it looks as through Schengen countries are reciporcating.

The new "authorisation" rules commence in 2021. This is not a punitive measure against the US.
We will all have to comply.

regards