Yes, U.S. companies should only build their plants in the United States. Over the past several decades, manufacturing jobs have largely left the United States in favor of other countries with lower manufacturing costs. This has caused mass unemployment in many parts of the country as well as the social problems that occur because of unemployment.
Companies do not have an obligation to keep plants in the United States. They have the right to build elsewhere if that is what's best for the company. However, I think the government should do what it can to give companies strong incentives to build factories in this country so that American workers can benefit as well.
The problem with American companies building plants overseas is not that it hurts workers in the United States. The problem is that the companies build factories in other countries because they can save money by exploiting the workers in those countries. If all workers in all countries were guaranteed reasonable pay, benefits and working conditions, I would have absolutely no problem with companies building plants overseas. The other problem is that American corporations often get huge tax breaks, or avoid paying taxes altogether, despite building most of their factories in other countries. They should not get these tax breaks if they build factories in other countries.
Coca-cola has a policy where they bottle their product as close to their actual markets as possible. This allows them to make a better product. It also makes for happy consumers because people in the local areas get to have jobs that are provided by the company they purchase goods from. It is good for world peace.