Both visits were ostensibly made to kickstart stalled peace talks between Kiev and the two Russian-speaking regions of eastern Ukraine that rebelled against the ex-Soviet republic’s westward shift in April, sparking months of fighting.
Belarussian President Alexander Lukashenko already hosted major peace negotiations in September and is hoping to do so again in Minsk in the coming days.
But Nazarbayev has no evident link to the eight-month conflict and along with Belarus remains a member of a Russian-dominated economic union that once had aspirations to enlist Ukraine.
A senior Ukrainian official said that both leaders criticised in the West for their intolerance of political dissent were now trying to shake off the Kremlin and forge partnerships in Europe because Russian President Vladimir Putin “is weak”.
Some political analysts in Russia agreed. “This is an unambiguous signal to Putin,” said Konstantin Kalachyov of Moscow’s Political Expert Group think tank.
“Both Kazakhstan and Belarus fear that their union with Russia will be engulfed by (an economic) crisis.”
Putin strongly denies accusations by the West that Moscow has been backing Ukraine’s separatist fighters. He says Western sanctions against his country are a remnant of Cold War-era thinking designed to contain Russia and possibly even topple his team.
The veteran Kremlin leader is due on Tuesday to receive both Nazarbayev and Lukashenko for a summit of leaders from neighbouring nations that have formed a loose military bloc.
But his relations with Lukashenko have been strained by the Belarussian strongman’s refusal to let Russian industrial giants take over his state companies in return for discounted energy deliveries.
The Kremlin’s top foreign policy adviser said Putin would meet separately in Moscow with Nazarbayev but had no such talks planned with the Belarussian head of state.
Nazarbayev has spent the past two decades carefully balancing his Central Asian country’s interests between those of Russia and China its southeastern neighbour and increasingly important trading partner.
Yet Nazarbayev said after his talks with Poroshenko that “Ukraine is closer to Europe (than Russia) and it would have been strange if the two did not work together or strike their association agreement” at the start of the year.
Nazarbayev branded the war in Ukraine’s east as “nonsense that should not be happening” and appealed for negotiations between Moscow and Kiev that would end the fighting and “preserved the territorial integrity of Ukraine”.
Lukashenko also seemed keen to cast himself as ready to stand up to Russia.
He appeared to be referring to Putin when he told the Ukrainian leader: “They keep saying that Lukashenko is afraid of someone. But I am not afraid.”
Belarussian state media then quoted Lukashenko as saying that he supported holding “secret” negotiations about building stronger cross-border ties with Ukraine.
“Let’s not say anything to anyone at all but do it in secret just as long as there is progress in this direction,” Lukashenko was quoted as saying.
The US and EU sanctions have cut off Russia’s biggest companies from Western money markets and put them in danger of going bankrupt.
And the Kremlin’s ability to provide their rescue has been limited by a recent fall in the global price on Russian oil and gas exports.
But the Western restrictions and a plunging ruble have hardly dented Putin’s domestic approval, still estimated at around 80 percent. Nor have the economic woes appeared to have significantly altered his public stance on Ukraine.
US President Barack Obama on Sunday dismissed the notion that Putin was “the chess master and outmaneuvering the West and outmaneuvering Mr Obama.”
“Right now, he’s presiding over the collapse of his currency, a major financial crisis and a huge economic contraction,” he told CNN.
Putin will have a chance to discuss the sanctions when he and Poroshenko hold a joint teleconference with German Chancellor Angela Merkel and French President Francois Hollande on Monday evening.