The World Health Organization (WHO) on Saturday formally declared Sierra Leone "Ebola free."

WHO Resident Representative to Sierra Leone Anders Nordstrom made the announcement after the West African nation has gone for 42 days without recording a single case of the Ebola virus.

The announcement was made at a ceremony held at the Chinese-built Bintumani Conference Center in Freetown, which was attended by Sierra Leone President Ernest Bai Koroma, UN representatives and foreign diplomats.

Nordstrom described the occasion as "a historic moment in the history of Sierra Leone and the world." He congratulated the president, government and people of Sierra Leone for their resilience.

The country has "built a resilient health care system that will deal with any infectious disease and at the same time stand the test of time," said the UN envoy.

Nordstrom reiterated WHO's continued support to the recovery phase.

In his keynote address, President Koroma said he is in consultation with the Parliament to end the "state of emergency" declared over one year ago.

The president declared Nov. 21 as a "national day of mourning for all those who lost their lives as a result of the virus" whilst Nov. 18 was declared a day to honor all Ebola workers.

Koroma said the country was able to defeat Ebola because of the participation of communities.

He voiced support for the WHO enhanced surveillance for the next 90 days, saying "we must remain vigilant and alert."

The president noted that the country was prepared for any re-emergence and a number of labs and treatment beds will be maintained to take care of "any re-emergence or any infectious disease in the future."

Koroma commended and thanked the international community for coming to the country's aid on the break of the outbreak.

Nearly 4,000 Sierra Leoneans lost their lives to the virus, with a similar number of survivors since the Ebola disease broke out. The country was hit by the disease over one year and eight months ago at exactly May 25, 2014.