If country A exports to country B, what do you call country B? Country A's 'export partner'? 'Export receiver'? I know the expression 'trading partner', but it includes both exports and imports.
I don't think "export partner" is a common way to say this, and it might be a bit confusing as to who is doing the exporting ("partner" also tends to imply a two-way relationship).
I think generally, people would instead tend to say something like:
Country B is Country A's biggest importer.
Country B is the biggest importer of goods from Country A.
This essentially means the same thing, because any goods which are exported by Country A must then also be imported by Country B to complete the transaction. This keeps it clear, however, who's doing the exporting and who's doing the importing.
In practice, any country that is an export partner will be a trading partner. There is no country that only exports and never imports.
However if you want to emphasise "a country which tends to receive exports" then "export partner" seems fine. Your readers will probably already know the facts, so they just have to align your new term to a fact that they already knew. As you are inventing a new term, you exemplify it.
Export partners of China, such as the USA and Canada want finished goods. Whereas import partners, such as many of the Middle East states....
Alternatively you can be completely clear by using a phrase such as "countries running a trade deficit with China"
You can always rephrase
China exports more to the USA than to any other country.