Suga, who took the top job in September after Shinzo Abe resigned citing illness, has enjoyed solid ratings of over 50%, buoyed by an image as a down-to-earth leader pushing popular policies such as lower mobile phone rates.

But critics said his reversal on a programme he has backed to bolster the economy even as new cases spiked was too little, too late, and risked leaving the image of a leader both stubborn and indecisive, without due care for public health.

"It's a display of indecisiveness that gives people a lot of reason to be resentful," said Sophia University professor Koichi Nakano. "At this point, they (the government) still sound like they don't know what they are doing."

Abe's own support ratings never recovered after sagging on the public's perception that his response to the pandemic was clumsy and slow.

Suga is currently serving out Abe's remaining term to next September and must win a ruling Liberal Democratic Party leadership race then in order to remain premier.

The policy fumble threatens his standing just two months into his premiership, with stiffer tests ahead, including the extent to which COVID-19 cases and deaths continue to rise, and whether Tokyo can host the postponed Summer Olympics in 2021.

"His ratings will decline, almost certainly," said independent political analyst Atsuo Ito, pointing to the delay in partially pausing the campaign. "The view may spread that he puts a priority on keeping the economy running rather than protecting people's lives."

In brief remarks on Saturday - after a three-day holiday was underway - Suga said the government would suspend new travel reservations to areas hard hit by COVID-19 under its "Go To Travel" programme, which subsidises tourism.

Critics of the programme have said it risks spreading the infection from major cities to the countryside.

On Tuesday, the government said Osaka and the city of Sapporo in Hokkaido would be excluded as target destinations in the travel subsidy programme. No decision has been made on the capital of Tokyo.

Government officials have repeatedly said travel itself does not spread infections if steps such as wearing face masks are taken.

However, Kyoto University professor Hiroshi Nishiura, an infectious disease expert and member of a government advisory board, said it was clear greater movement of people boosted infection risk.

Experts advising the government - who on Friday had finally urged a partial pause in the Go To programme - had been "somewhat forced" to accept policies to help the economy despite such increased health risks, he told Reuters.

Opposition parties, who are also linking Suga to an alleged Abe funding scandal, quickly chimed in with criticism.

"The timing of the announcement was too late and both the timing and target areas are not clear," Tetsuro Fukuyama, secretary general of the opposition Constitutional Democratic Party of Japan, said on television.

Suga's long-term future hinges on the outcome of a general election that must be held by October 2021.

"If the LDP loses a lot of seats, he may be held responsible," said University of Tokyo political science professor Yu Uchiyama.

($1 = 104.4800 yen)