* Putin's chief of staff says Russian leader in good health
* Kremlin calls public discussion of possible visit dates "unethical"
* Russia denies visit had been set for December
By Kiyoshi Takenaka and Alexei Anishchuk
TOKYO/MOSCOW, Nov 30 (Reuters) - Vladimir Putin is in good health, his chief of staff said on Friday after Japanese media said Prime Minister Yoshihiko Noda had postponed a visit to Moscow next month because the Russian president had a health problem.
A former KGB officer who enjoys vast authority in Russia, Putin has long cultivated a tough-guy image, and health issues could damage that. His condition though has been questioned in some media since he was seen limping at a summit in September.
Three Russian government sources told Reuters late in October that Putin, who began a six-year term in May and turned 60 last month, was suffering from back trouble, but the Kremlin has dismissed talk that he had a serious back problem.
Putin's health troubles stem from a recent judo bout, Belarussian President Alexander Lukashenko said this week.
Then on Friday Japanese news agencies Kyodo and Jiji reported that Prime Minister Noda talked about the delay of a visit planned for December in a meeting with municipal officials on the northern island of Hokkaido.
"It's about (President Putin's) health problem. This is not something that can easily be made public," Jiji cited one of the officials as quoting Noda as saying.
But Putin's chief of staff Sergei Ivanov denied there was any problem.
"Please don't worry, don't be concerned. Everything is in order with his health," Putin's said in Vienna, according to state-run Russian news agency RIA.
In an interview published on Friday in the popular Russian tabloid Komsomolskaya Pravda, Putin's spokesman Dmitry Peskov said rumours about a spine problem were "strongly exaggerated".
"He is working as he has before and intends to continue working at the same pace," Peskov said.
"He also does not plan to give up his sports activities and for this reason, like any athlete, his back, his arm, his leg might sometimes hurt a little - this has never gotten in the way of his ability to work."
Putin had been expected to make several foreign trips in late October or November, but they did not take place.
Putin is however due to visit Turkey on Monday and Turkmenistan on Wednesday.
Putin's foreign policy adviser, Yuri Ushakov, made amply clear the Kremlin was displeased by the public discussion of scheduling by Japanese officials and denied that Noda's visit had been postponed, saying no date had been set.
"It is just unethical to name the dates that were discussed. There were several: at first it was October, November, December, January ... then we even shifted to February," Ushakov said, adding that the sides eventually agreed tentatively on January.
He said the diplomatic process of agreeing dates for the visit should have been "hermetically sealed".
Putin's image as a fit, healthy man helped bring him popularity when he rose to power 13 years ago because of the stark contrast with his predecessor Boris Yeltsin, who was sometimes drunk in public and had heart surgery when president.
He has used activities like scuba diving and horseback riding to maintain that image.
On Friday, Putin met leaders of parliamentary factions in his Novo-Ogaryovo residence outside Moscow. He appeared in good health and was walking without any sign of a limp.
Likely to be on the agenda in talks between Russian and Japanese officials are energy cooperation and a decades-old dispute over islands north of Hokkaido known as the Southern Kurils in Russia and the Northern Territories in Japan.