Translation of "Regrettable" in Finnish

I made a regrettable mistake.

Minulle on tapahtunut valitettava erehdys.

It is regrettable that I can't go with you.

Harmi, etten pääse mukaan.

- That, while regrettable, is true.
- It may be a pity, but it's true.

Vaikkakin se on valitettavaa, niin se on totta.