The EU has urged member states to coordinate closely as they ease their coronavirus lockdowns, while the World Health Organization (WHO) warned that all transitional steps back to normal life must be taken cautiously and evaluated carefully.

As the number of Covid-19 cases passed 2m worldwide on Wednesday, with more than 80,000 deaths in Europe, countries including Austria, Denmark and the Czech Republic have all made small-scale moves to lift some restrictions.

Spain and Italy, the worst affected EU nations, have renewed their lockdowns but begun allowing some non-essential workers back to work, while France has said it will start easing restrictions from 11 May.

Germany, which on Wednesday announced its highest daily death tally but its lowest ever increase in new cases, will partially reopen schools from 4 May, at first for children in their final years of primary or secondary school, with smaller shops as well as bookshops, bike stores and car dealerships, to open from the following Monday.

Anxious to avoid the chaos that ensued when EU governments began imposing individual measures to contain the pandemic, the European commission said lifting restrictions would “unavoidably lead to a corresponding increase in new cases”.

The commission said in its roadmap that all action should be gradual and coordinated, stressing that any other approach risked “negative effects for all member states” and could lead to political frictions.

In its latest strategy update, the WHO advised a wait of at least two weeks to evaluate the impact of any changes before easing restrictions again, stressing that the world stood at a “pivotal juncture” in the pandemic and “speed, scale and equity must be the guiding principles” when deciding what measures are necessary.

Social distancing should be maintained and there should be no general return to work, the commission recommended in its paper, and limits should be considered on the number of customers and pupils allowed in shops and classrooms.

Elderly people must be protected for longer, while restaurants, bars and cinemas could reopen with restricted opening hours and limits on customer numbers. Bans on mass gatherings like festivals and concerts should be among the last to be lifted.

The commission also said it could be a year before a vaccine was widely available and urged a massive increase in testing, performed in the same way across the bloc. Data collection, including through apps on mobile phones, could reduce the risk of further transmission but should be voluntary, it said.

According to the Johns Hopkins university tracker, the coronavirus has infected nearly 2,000,100 people and killed 128,000 around the globe. More than one third of humanity is living under some form of lockdown restrictions.

In countries where the outbreak has passed or is near its peak, leaders are wrestling with difficult decisions over lifting containment measures to jump-start economies and avert crippling recession, while still avoiding a second wave of infections.

Italy has allowed bookshops, laundries, stationers and children’s clothing stores to re-open on Tuesday - although many decided to stay shut - while Spain allowed work to restart in some factories and construction sites, and Denmark reopened its schools.

Bill de Blasio, the mayor of New York City, now firmly established as the heart of the global crisis after revising its death toll sharply upwards to more than 10,000 people, also urged a cautious and deliberative approach to reviving the economy, warning that moving too quickly could create an opportunity for the coronavirus to resurface.

“We cannot allow that,” De Blasio said. “We get one chance to get it right. I think we have to be smart about doing it in stages, making sure that we can confirm that we’re containing the disease more and more, getting it back to where it was a month or two ago, before we start to open up a lot.”

Elsewhere, people braced for several more weeks of restrictions. Japan on Wednesday urged its citizens to stay at home as media cited an unpublished health ministry projection suggesting as many as 400,000 could die without mitigation and 850,000 could end up needing ventilators.

Japan has so far recorded more than 9,000 infections amid an accelerating infection rate in recent weeks, particularly in Tokyo. The government has declared an emergency in Tokyo and six other areas including Osaka, and a goal to cut interactions between people by 70% – although there are no fines or penalties.

Meanwhile the virus is slowly taking hold in Africa, with 15,000 cases and 800 deaths continent-wide as fears mount over growing hunger and possible social unrest. “A lockdown is unenforceable and unsustainable across much of Africa,” said Jakkie Cilliers of the Institute for Security Studies (ISS) in Pretoria, South Africa.

“You are trying to do something that is not possible, and you are condemning people to a choice between starving and getting sick,” he said. “It’s not possible for 10 people living in a tin shack... to not go outside for three weeks.”

In South Korea, meanwhile, more than 17 million people wore masks and disposable gloves to vote in parliamentary elections – the highest turnout in nearly three decades despite the coronavirus, with another 11.8 million casting their ballots early.

South Korea has been widely praised for its success in using mass testing and contact tracing to contain the spread of the virus, and to hold the elections as scheduled, officials and health authorities carefully prepared safeguards to reduce the risk.

In the US, which on Tuesday counted a record of 2,228 victims over the past 24 hours, Donald Trump sparked global outrage by announcing that Washington would halt payments to the WHO amounting to about $400m last year.