PAL DVD players are capable of playing NTSC but most American DVD players aren't capable of playing PAL.

So if you're looking to create one disc for both European and American friends, you're best creating it as NTSC.

Or are you asking about video that will played online or on a computer?

If your friends are going to view your video on a computer or strreamed, it doesn't matter which standard you choose. So I'd recommend 30 fps non-interlaced.

Or do you have another way you plan to distribute your movie?

As you are writing your video to a USB flash drive, I'd probably go with an MP4 (H264 or H265) rather than the older format of MPEG-2. I'd check with the recipients what they prefer, if they are not too many.

As StevenG says, it's only when your are burning to a DVD that you need to concern yourself about NTSC/PAL.

Thanks for the advice.
I thought that was the case regarding the necessity for concern about NTSC/PAL. only in relation to burning to a DVD.
The plan for the USA is that thry will play the video throygh a computer or the smart TV.
I have produced in Mpeg2, but I will redo in Mpeg4.

Just a thought, which may or may not be of interest, if you are sharing with friends/relations in USA and Canada as I do - YouTube is a great way of doing this very quickly, no postage and no risk of items getting 'lost in the post'. YT has an option for uploaded files "Unlisted" which means that although anybody can watch the video, you can only do so if you know what the URL is. The files are sort of semi-private.

Yes, Thanks.
I'm aware of that option, slthough, I've never tried it. The video is a present on a personalised usb and that is why in this case I ma sending it to them. But, appreciate all and any advice.