I told him I have been to this country many times before, and I always felt safe there. I told him I would call him daily, and he can email me.
This is just another way of telling him not to worry, which is well-intended but invalidating.
And the truth is, if I thought that my spouse would be injured (or they were going with someone else) I would be upset too. No matter how unrealistic those things are.
That's validating!

He's worried and anxious - let him know you hear him! Don't try to reassure him that you'll be fine. Something more along the lines of "You sound worried for me hon,
but I'll be fine I know you want to look out for me." That's about all you can do. Don't make a big deal about it. Be business like about this . . . and then go!