A man communicates with a customer through the door of a market in Dongsi Subdistrict on February 24, 2020 in Beijing, China.

The World Health Organization warned countries on Tuesday to be prepared for the coronavirus to be "literally knocking at the door."

The warning comes amid intensifying concern about the coronavirus outbreak, with the deadly flu-like virus spreading to more than two dozen countries in recent weeks.

Speaking in Geneva, Switzerland, WHO spokesperson Christian Lindmeier said some countries had "pandemic plans" on standby in a bid to prevent the outbreak, Reuters reported. But, while many were ready to act upon them depending on their situation, Lindmeier said the WHO was not planning a "big announcement."

Late last month, the WHO declared China's fast-spreading coronavirus a global health emergency.

Lindmeier's comments appeared to confirm the United Nations health agency would not declare the deadly flu-like virus as a pandemic over the coming days.

As of Tuesday, China's National Health Commission reported 77,658 confirmed cases of COVID-19, with 2,663 deaths nationwide.

South Korea, Italy and Iran have all recorded a sharp uptick in cases of the coronavirus in recent days, with many other countries imposing travel restrictions on virus-hit areas worldwide.

Lindmeier said officials meeting in Rome to discuss "pretty strong" measures implemented in Italy.

A WHO mission to Iran has been delayed, Lindmeier said, with no new date for departure. The mission was initially scheduled to arrive in the Islamic Republic on Tuesday.