TOKYO — It's a state of emergency over Tokyo, but no lockdown.

On Tuesday, Japanese Prime Minister Shinzo Abe declared a state of emergency for about a month in Tokyo and six other prefectures most severely affected by the coronavirus.

In a televised news conference, Abe asked people to refrain from going outside needlessly. But he said that the government “will not lock cities down as has been done overseas” and that economic activity will be maintained as much as possible. He also announced an “unprecedented” economic rescue package, equivalent to about 20 percent of Japan’s gross domestic product.

“It is of the utmost importance to change the behavior of citizens,” Abe said. “If all of us make an effort and try to reduce person-to-person contact by 70 percent or, preferably, 80 percent, the increase in infections will peak in two weeks and shift to a decline.”

Abe said Japan was not seeing a rapid nationwide spread of the virus, but he cautioned that the medical systems in some regions were under pressure, “so we have no luxury of time.”

The state of emergency covers Tokyo and three surrounding prefectures, plus the city of Osaka and two other prefectures in southwestern Japan.

The announcement exasperated many people.

The government, they say, has dithered in the face of an explosion in infections in the capital and is still reluctant to impose the sort of extreme measures necessary to contain the virus — largely because of concerns about the economic impact.

“It’s too late,” said Kenji Shibuya, director of the Institute for Population Health at King’s College, London, who warned that the Japanese capital could soon face the sort of calamitous rise in infections and deaths that New York is experiencing.

“Tokyo has already entered an explosive phase, and the only way to stop the collapse in health care was to lock down the city as early as possible.”

Abe urged people not to leave Tokyo or Osaka, since they could spread the virus to smaller towns where many vulnerable elderly people live. “What we have to fear is fear itself,” he said, echoing President Franklin D. Roosevelt’s memorable 1933 remark during the Great Depression. He argued that the risks of infection in Tokyo were “not really high” compared with overseas cities where more extensive lockdowns were put in place.

But he asked people to avoid going to bars, nightclubs, karaoke parlors or live music venues and to refrain from dining out in large groups — although there will be no penalties for noncompliance. Walking and jogging are fine, he said, while restaurants should be well ventilated and put space between diners.

He asked companies to institute remote working where possible — or at least stagger working hours and reduce contact among employees. Schools will remain closed, but trains and buses will run, and “essential” services will stay open, he said.

But what constitutes an essential service? Tokyo Gov. Yuriko Koike said she would provide details by Thursday of places asked to close their doors. But under a draft plan obtained by the Mainichi newspaper, health-care facilities, supermarkets, convenience stores, hotels, factories and public baths will remain open, while restaurants may be asked to cut their hours.

Museums, libraries, cinemas, Internet cafes, department stores, malls and gyms may be asked to shutter, although there may be exceptions for small businesses.

For many experts, this is too little, too late.

Infections are surging in Japan, with about 250 new cases reported Monday and the cumulative total topping 4,100. It’s in the capital that the crisis is most acute, with more than 1,000 people hospitalized and beds already at full capacity.

The hazard lights were flashing two weeks ago, as experts warned that a second wave of infections was taking hold. But restaurants and bars were still busy, and thousands of pachinko parlors — crowded, smoky venues that host a form of legal gambling — remained open.

Six days ago, the Japan Medical Association warned that the medical situation had become critical and urged the government to declare a state of emergency.

The same day, the Japanese Society of Intensive Care Medicine said the country had only five intensive-care units per 100,000 people, half the level of Italy, and warned that “a surge in terms of the number of deaths will come very soon.” The government’s expert panel then said it was “highly likely” that the disease was rampant.

That, said Shibuya, was pretty much the last chance to stop the explosion.

Part of the problem: The ruling Liberal Democratic Party has extremely close ties with the business community, while Abe is keen to preserve his long attempt to revive Japan’s sluggish economy, policies known as Abenomics.

So while Abe moved swiftly to ask schools to close at the end of February — even though his expert panel said such a move was premature — he has been much slower to take action that would undermine the economy.

Japan has been lulled into a false sense of security partly by a lack of widespread testing for the virus but also by its early success in containing the epidemic, which was based on tracing and isolating clusters of infections.

There was also a sense of exceptionalism: that the widespread use of masks, good standards of hygiene and lack of physical contact were helping to contain the virus, and that the country could avoid the sort of dramatic lockdowns seen elsewhere.

Koichi Nakano, a political science professor at Sophia University, said the lack of testing created a lack of transparency, while policies were incoherent and lacked direction.

“The government is so much more focused on trying to provide lifelines to the corporate sector,” Nakano said.

Shibuya said the government’s expert panel lacked the wide range of talents that was needed and excluded the sort of outspoken academics who might have raised the alarm earlier. Instead, the panel has fallen in line behind a set of policies that suits the agenda of the government and the corporate sector.

But in recent days, the tide has begun to turn, with big businesses moving in favor of firmer action.

“They want to see conditions resolved sooner — even at the expense of immediate pain,” said Takahide Kiuchi, executive economist at the Nomura Research Institute. “It is small businesses that wanted Abe not to act so soon.”

Akiko Kashiwagi contributed to this report.