TOKYO (BLOOMBERG) - Japanese Prime Minister Shinzo Abe should be able to serve out the remainder of his term as party leader ending about a year from now, his right-hand man said, after recent hospital visits raised questions about the premier's health.

Chief Cabinet Secretary Yoshihide Suga, 71, said in an interview with Bloomberg on Thursday (Aug 27) that he expects Mr Abe to explain his health condition in a proper way.

Mr Abe on Friday is set to give his first full news conference since June, at which time he's expected to discuss coronavirus policy as well as his own health.

"Of course," Mr Suga said, when asked whether Mr Abe could withstand another year in a physically demanding job that sometimes requires weeks in a row in parliamentary committees. "He'll be all right," he said, adding that he saw no change in his condition.

At the news conference Friday, Mr Abe is expected to unveil a government plan to secure a coronavirus vaccine for the entire population by the first half of next year, national public broadcaster NHK reported, without saying who provided the information.

The 65-year-old prime minister has visited Keio University Hospital twice in the past two weeks, telling reporters that he was undergoing tests to maintain his health.

Although the government has provided few details, domestic media have said he was actually undergoing treatment for ulcerative colitis, a chronic digestive condition that forced him to step down as premier in 2007.

The yen weakened as much as 0.2 per cent to 106.20 against the dollar before paring losses after Mr Suga's comments were reported.

Analysts said the currency could strengthen if Mr Abe were to step down given his so-called Abenomics has helped keep the yen in check since 2013.

Mr Abe's current term as leader of the ruling Liberal Democratic Party (LDP) ends in September of next year. The party has run the country for most of the last 65 years, and the LDP leader is almost assured of serving as prime minister. Surveys show it having a commanding lead over a fractured opposition.

Mr Suga has worked closely with Mr Abe since he swept to office a second time in 2012, helping him win six straight national elections.

Mr Abe's health concerns have raised questions about succession in the LDP, with Mr Suga's name being listed among possible contenders.

The lack of open dissent in the LDP has been one of the reasons Mr Abe has endured to become Japan's longest-serving prime minister. Some potential candidates may be holding fire while he's in office, but a large degree of continuity is likely in managing the world's third-largest economy.

Mr Suga has emphasised the importance of reviving the economy even amid a second wave of virus cases, after Japan suffered its worst economic downturn on record in the April-June quarter.

A state of emergency over the infection that was lifted in late May, effectively closed many businesses for weeks during that period.

Mr Suga has pushed policies including subsidies for travel and eating out, even as critics said they risked worsening the infection's spread. Japan has seen by far the lowest death toll among Group of Seven advanced countries.

"However many times I'm asked, I'm not thinking of it at all," Mr Suga said when asked if he hoped to succeed Mr Abe.

"Anyway, there's still another year to go."