The president of Ukraine has condemned a move by parliament to dismiss the government as "unconstitutional".
Mr Yushchenko also discussed the gas dispute with Russia
The "decision was incomprehensible, illogical and wrong," Viktor Yushchenko told reporters in the Kazakh capital.
He also held talks with Russian leader Vladimir Putin in Astana, where they had both gone for the inauguration of Kazakh President Nursultan Nazarbayev.
It was their first meeting since Russia turned off Ukraine's gas in a row over fuel prices.
They said the deal that ended the dispute was good for everyone and would not be renegotiated.
But they gave few other details about their discussion, the BBC's Ian MacWilliam in Kazakhstan says.
On his arrival in Astana, Mr Yushchenko criticised his parliament for its vote to sack the government on Tuesday.
The no-confidence vote was backed by 250 of the assembly's 450 deputies, but President Yushchenko plans to challenge the vote in the Constitutional Court.
GAS ROW TIMELINE
Nov 2005 - Russian gas giant, Gazprom, demands Ukraine pay market rates for gas supplies
13 Dec - Gazprom threatens to cut supplies if deal not reached by 1 January
28 Dec - Ukraine's energy minister visits Moscow but fails to resolve row
1 Jan 2006 - Russia cuts off gas supplies to Ukraine
3 Jan - EU calls for end to row, as supplies across Europe hit
4 Jan - Deal reached. Ukraine agrees to pay Russia double for gas supplies
10 Jan - Ukraine's parliament votes to sack cabinet over deal
He says parliament does not have the authority to dismiss the government.
It was the second time in six months that a Ukrainian government had been sacked.
Moscow cut gas supplies to Ukraine on 1 January when it refused to pay a four-fold increase.
The disruption to supplies affected a number of European countries.
Ukraine now pays double the previous price, at $95 (£54) per 1,000 cubic metres of gas.
President Yushchenko said he struck the deal with Russia in order to avoid months of gas shortages.
Central Asian ambitions
Our correspondent says the Ukrainian leader reportedly wants to discuss possible routes for new gas pipelines from Central Asia, to lessen his country's dependence on Russian gas.
The Karachaganak gas field in Kazakhstan is one of the world's largest and it is due to significantly increase production in the next few years. Central Asia's leaders would also like new export routes for their abundant gas and oil.
Currently, they can only export their gas through Soviet-era pipelines through Russian territory.
Russia's deal with Ukraine was only possible because Russia buys extra gas cheaply from Turkmenistan and Kazakhstan and will now re-sell it at twice the rate to Ukraine.
With more control over their export pipelines, the Central Asians could demand world market prices.