The global coronavirus outbreak has been declared a pandemic by the World Health Organisation which expressed increasing concern about the spread of the disease and "alarming levels of inaction".
The UN agency said there is a "lack of resilience" in the public health systems of some countries as it called for better tracing of those who have come into contact with infected cases.
There have been more than 121,500 confirmed cases of COVID-19 , the prevalent strain of coronavirus, in at least 114 nations in the pandemic - which is defined as a new virus sparking sustained outbreaks in multiple regions of the world.
More than 4,300 people have died, including over 3,000 in China, the epicentre of the disease.
By using the word pandemic - which it previously shied away from - the WHO is trying to shock more lethargic nations into taking increased action.
But the head of the organisation said it is not too late for nations to act - and all countries can still change the course of the outbreak if they detect, test, treat, isolate, trace and mobilise their populace.
The WHO said Italy and Iran were now on the frontline of the disease - which started in China late last year - and other countries would soon join them.
Outside China, there has been a 13-fold rise in the number of infections and a tripling of the countries affected in the last two weeks.
In the second worst hit country Italy , which has been put on lockdown this week, the number of dead nationally has risen by 196 to 827 in a day - a jump of 31%.
Deaths in the most severely hit region of Lombardy in the north have increased from 468 to 617.
The number of cases in the region - which includes Italy's financial capital Milan and has seen the majority of infections - has risen by 1,489 in the last 24 hours, Reuters reported.
Speaking about the worldwide situation, the WHO's director general Dr Tedros Adhanom Ghebreyesus said: "We have called every day for countries to take urgent and aggressive action. We have rung the alarm bell loud and clear.
"All countries can still change the course of this pandemic. If countries detect, test, treat, isolate, trace and mobilise their people in the response."
Dr Tedros added: "We are deeply concerned both by the alarming levels of spread and severity and by the alarming levels of inaction.
"We have therefore made the assessment that COVID-19 can be characterised as a pandemic."
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Dr Tedros went on: "In the past two weeks, the number of cases of COVID-19 outside China has increased 13 fold and the number of affected countries has tripled."
He urged the global community to redouble efforts to contain the outbreak, saying aggressive measures could still play a big role to curb the pandemic.
The head of the organisation's emergencies programme, Dr Mike Ryan, said the WHO's use of the word pandemic does not change its response.
He also told a news conference that the situation in Iran was "very serious" and the agency would like to see more surveillance and more care for the unwell.
Iran's senior vice president and two other cabinet members have contracted the new coronavirus, as the death toll there rose by 62 to 354.
Dr Ryan said of Iran and Italy: "They're suffering but I guarantee you other countries will be in that situation soon."
The number of people with the coronavirus in the UK has risen to 460 after a further 87 tested positive for the disease in the last 24 hours.
The figure is the biggest daily increase so far in coronavirus cases in the UK , where eight people have died after contracting the virus.
According to the WHO website, a pandemic is defined as the worldwide spread of a new disease. It can also refer to a disease which is prevalent over a whole country.
In contrast to a pandemic, an epidemic refers to the spread of illness in a "community or region...clearly in excess of normal expectancy".
According to a 2017 report, the WHO has four phases to describe the outbreak of a pandemic.