The coronavirus "may never disappear", warned the World Health Organization (WHO).
Speaking at a briefing on Wednesday, WHO emergency director Mike Ryan warned against trying to predict when the virus will disappear.
He added that even if a vaccine is found, controlling the virus will require "a lot of effort".
It is reported that almost 300,000 people worldwide have died from coronavirus and more than 4.3 million cases have been reported.
Meanwhile, the UN has warned that the pandemic is causing widespread suffering and mental health problems – particularly in countries where there is a lack of investment in mental health.
The UN urged governments to make mental health considerations part of their overall response.
What did WHO say?
"It is important to put this on the table: this virus can become just another virus endemic in our communities and it can never disappear," Ryan said at a virtual news conference in Geneva.
"HIV has not disappeared – but we have come to terms with the virus."
Ryan then said he did not believe that "anyone can predict when this disease will go away".
There are currently over 100 potential vaccines in development – but Dr. Ryan noted that there are other diseases, like measles, that have not yet been eliminated, despite vaccines for them.
WHO Director-General Tedros Adhanom Ghebreyesus emphasized that it is still possible to control the virus with effort.
"The trajectory is in our hands, and it is everyone's business, and we must all contribute to ending this pandemic," he said.
WHO epidemiologist Maria van Kerkhove also told the briefing: "We need to get into the mindset that it will take some time to get out of this pandemic."
Their harsh observations come when several countries have begun to gradually reduce blocking measures, and leaders consider the question of how and when to reopen their economies.
Dr. Tedros warned that there was no guaranteed way to ease restrictions without triggering a second wave of infections.
"Many countries would like to move away from the different measures," said the head of WHO. "But our recommendation is still the warning in any country that should be at the highest possible level."
Dr. Ryan added, "There is some magical thinking going on that the locks work perfectly and that the unlocking locks will be great. Both are fraught with danger."