Russian officials have denied reports that Vladimir Putin has fallen ill after the cancellation of two state events, but admitted the president’s schedule due to the Ukraine crisis was “very intensive”.

Representatives from both countries confirmed that Mr Putin had postponed a visit to Kazakhstan, and a Kazakh government official told the Reuters news agency: “It looks like he has fallen ill.”

Speaking to a Moscow radio station, the president’s spokesman Dmitry Peskov insisted Mr Putin was “absolutely” healthy, adding that Mr Putin's handshake was still so strong it could “break your hand”.

On Wednesday the Kremlin cancelled a ceremony in Russia to formalise their claim that they have annexed South Ossetia – at such short notice that a delegation from the region had already arrived in Moscow, according to Russian media.

The president has not been seen in public since he met with the Italian Prime Minister Matteo Renzi in Moscow. An image released yesterday by Mr Putin's press team showed a meeting with the regional governor of Karelia that, according to various news agencies, actually took place on 4 March.

Mr Peskov was unable to say when Mr Putin would next be making a public appearance, and said he would not be appearing at a meeting with the Federal Security Service today, which he often attends.

“Yes, he's usually there,” Mr Peskov said. “But this year he was not planning to be.”

Mounting speculation has filled the gap left by the lack of solid information on Mr Putin's health, though the rumours seemed to have little impact on financial market. BBC Panorama's John Sweeney - who famously doorstepped Mr Putin to ask him if he “regrets the killings in Ukraine” last year - asked on Twitter whether he was suffering “manflu or [a] life-changing stroke?”

Dmitry Peskov told the RIA news agency that the president was in constant contact with state companies and banks as well as government officials, but admitted that he was busier than usual because of the ongoing situation in Ukraine.

“He has meetings all the time, but not all meetings are public,” Mr Peskov said. “The agenda is very intensive - linked to the crisis and so on.”

It is incredibly rare for Mr Putin to miss state events through illness, and the Kremlin is quick to deny any hints of weakness on the part of the 62-year-old.

In 2012 his people denied any problems despite Mr Putin being seen in public with a limp and a range of sources saying he was having back trouble. In October, Mr Peskov told journalists to “shut their trap” after the New York Post carried reports that Mr Putin may have pancreatic cancer.

9 controversial Putin quotes Show all 9 1 /9 9 controversial Putin quotes 9 controversial Putin quotes 2004 “Anyone who doesn't regret the passing of the Soviet Union has no heart. Anyone who wants it restored has no brains.” Getty images 9 controversial Putin quotes December 2005 “There is no such thing as a former KGB man.” Getty images 9 controversial Putin quotes G8 Summit press conference 2008 “If you want to become an Islamic fundamentalist and be circumcised, come to Moscow. We are multiconfessional. We have very good specialists. I can recommend one for the operation. He'll make sure nothing grows back.” Getty images 9 controversial Putin quotes 2010 “Russia doesn't negotiate with terrorists. It destroys them.” After the Moscow Metro bomb Getty images 9 controversial Putin quotes September 2013 “They say that Pyotr Ilyich Tchaikovsky was a homosexual. Truth be told, we don’t love him because of that, but he was a great musician, and we all love his music. So what?” Interview with Associated Press Getty images 9 controversial Putin quotes March 2014 “The West’s leaders seem, from what they say, entirely to have forgotten that there are some leaders in the world who want to conquer other countries.” Getty images 9 controversial Putin quotes 2014 Amazingly elaborate metaphor regarding the West and Russia “[Sometimes I think] our bear should probably just sit quietly and just eat honey instead of hunting animals, maybe then they will leave the bear in peace, but, no, they will not. What they are trying to do is chain the bear, and when they chain the bear they will take out his fangs and claws. This is how nuclear deterrence is working at the moment. If they take out the bear’s fangs and claws, then the bear will not be able to do anything. It will just be a stuffed animal.” Russian President’s annual press conference Getty images 9 controversial Putin quotes 2014 After Ksenia Sobchack, a well-known anti-Kremlin activist and journalist, was allowed to ask a question about Putin’s government suppressing opposing political viewpoints: “Why did you give her the floor?” Russian President’s annual press conference Getty images 9 controversial Putin quotes January 2014 “You can feel relaxed and calm [in Russia], but leave children alone, please.” Directed at gay people in January 2014, before the Sochi Winter Olympics Getty images

The president's visit to Kazakhstan was scheduled this week as a show of support for the Kazakh President Nursultan Nazarbayev, who has revealed he intends to extend his 26 years in charge of the country with a snap election next month.

Dauren Abayev, adviser and spokesman for Mr Nazarbayev, said the meeting of the two allies had been “delayed” but did not provide a reason or a new date.

The president of Belarus, Alexander Lukashenko, had also been expected to join Putin and Nazarbayev for talks in Astana to discuss economic cooperation, the conflict in Ukraine and other issues.