England - Crystal Palace winger could yet decide to play for Ivory Coast, the country of his birth, even if he makes his England debut in a friendly against Sweden on Wednesday.
The 20-year-old, who left West Africa as a four-year-old, told British media on Tuesday that he was still undecided about which country he would ultimately opt for.
"It's 50-50 because I was born in Ivory Coast but all I know is England," he told the Guardian newspaper.
"When the time comes, I'll make a choice. For now I just want to reach the top."
Wednesday's match in Stockholm is classed as a non-competitive game by Fifa, which means Zaha would not be committing himself to England long-term if he makes an appearance.
Zaha is only the second Championship (second tier) outfield player in five years to be called up by England. He has played five times for England's under-21s.
Ivory Coast also have their sights on him, however, with Didier Drogba reportedly calling to urge him to commit to the country of his birth.
The Sun newspaper quoted former Chelsea striker Salomon Kalou, now with Lille in France, as saying: "I'm unhappy Zaha has chosen England - he is Ivorian and his place is with us.
"He must remember it is not easy to play for - and triumph - with England."
Zaha may not have long to make his decision with Ivory Coast playing in the African Nations Cup finals starting in South Africa in January.