Source 10 (NPR) directly and explicitly states in its headline, 'China vows retaliation and a \'fight to the end\'' in response to US tariff threats. This is strongly corroborated by other credible sources, such as Source 4 (CNN) and Source 5 (BBC), which quote Chinese officials stating the nation is 'not afraid' of a trade war, confirming a consistent and defiant stance.