To be deductible, the charity must be registered in the US as a tax-exempt organization. There is a search tool here,
https://www.irs.gov/charities-non-profits/tax-exempt-organization-search
Some overseas charities have US branches, but others do not, so it depends on who you donated to.
Then, you can always list qualifying charitable donations on your tax return, but how much benefit you get depends on your other itemized deductions (mortgage interest, state and local taxes) and other filing situations that we don't know about.
