As an international instructor, should I openly talk about my accent?
Accents are tricky, especially in large lecture halls where students hear you over a mic, and can't see your lips. Different regions might have different opinions on what accents are difficult, depending on what other native language groups the undergrads may have been exposed to.

In my opinion, it would go a long way for your undergraduates to say something like:


  As you may have noticed, English isn't my first language. I know sometimes that makes it hard to understand certain words. Please don't hesitate to ask me to repeat something.


This might help with students who are shy or don't want to offend you by asking. 

If you like, you could mention the other languages you're familiar with to encourage speakers of those languages to connect with you, or just as a fun fact (personally, I'd be curious to know). I wouldn't mention it to make yourself seem somehow better than them, as that could needlessly add feelings of resentment.