Pentax has two assemblent plants in Vietnam. Those are owned and run by Pentax.
They are assemblent plants which means they put together pieces made elsewhere, and those pieces comes from Japan. That is why the term "Assembled in Vietnam" is used.
It is the same thing with the cameras assembled in the Phillipines. Pentax does not make the parts themselves, they buys from others and puts those parts together.
The lens elements are finished and coated in Japan, by Hoya. It is Hoya's speciality...
Then they are shipped to Vietnam and assembled in the lens.
To those afraid of Pentax products from China - Pentax closed down their own factory in China when Hoya took over. The Optios were made there. I have an Optio 30 made there, and this beauty is a fantastic digicam. Not fast, but delivers great and sharp and colourful images.
Now many of the Optios comes from Taiwan, by an OEM maker.
But Taiwan is also China...