A German media outlet says that the World Health Organization's (WHO) decision in January to delay the declaration of a pandemic for the novel coronavirus was caused by pressure from Chinese President Xi Jinping.

Quoting Germany's federal intelligence service BND, the German magazine Der Spiegel reported on Saturday that Xi called WHO Director-General Tedros Adhanom Ghebreyesus on January 21 and asked him to hold back information about the disease being transmittable between humans and delay the pandemic declaration. 

BND reportedly assessed that the delay cost the world four to six weeks in the fight against the virus.

The WHO, however, denied the report, calling the allegations "unfounded and untrue." It claimed that the WHO chief and President Xi did not speak on January 21, nor have they ever spoken by phone.