Unless the recipient is subject to reporting 1099 income to the U.S. (non-exempt), you do not need to report payments to them on a Form 1099-MISC.
They are considered Exempt recipients. An exempt recipient
is any payee that is exempt from the
Form 1099 reporting requirements.
If the foreign recipient is non-exempt (i.e. subject to Form 1099 reporting requirements), the IRS suggests
that you request the recipient complete the appropriate
Form W-8.
(Payments to foreign persons. See the Instructions for
Form 1042-S, relating to U.S. source income of foreign
persons, for reporting requirements relating to payments
to foreign persons, at https://www.irs.gov/pub/irs-pdf/i1042s.pdf)
