Technically it belongs to North America, but people tend to divide it into three parts.
The connection between Central America and North America is by an isthmus, not an another continent.
North America.
Central America is part of the North American continent.
The continent of North America or the North American continent
The North American Continent
The United States of America is located on the North American continent.
No part of Canada is a continent in itself. The entire country of Canada is a part of the continent of North America.
The US is in the North American Continent.
America is on the North American continent.
Neither. There is no such continent as "Central America" its a term with no specific meaning. There is a North American continent, and a South American continent, but no Central American continent. El Salvador is located on the North American continent.
American Continent.