Speaking in a televised interview with some hand-picked journalists, President Viktor Yanukovych criticized foreign nations for meddling in Ukraine's internal affairs.
Senior Western diplomats have in recent weeks attended and expressed support for the sprawling demonstrations on Kyiv's Independence Square, known as the Maidan. Assistant U.S. Secretary of State Victoria Nuland even gave out sandwiches to protesters there.
"It is very important. This is our internal matter," Yanukovych said. "Some countries should not meddle in our internal affairs and should not believe that they can be the bosses here."
"I am categorically against having someone come here and teach us how to live," a visibly angered Yanukovych added.
Yanukovych has faced nearly a month of angry protests since his abrupt decision to shelve a political and trade agreement with the 28-nation European Union and turn toward Russia instead. The rallies grew larger, swelling to hundreds of thousands, after riot police violently broke up the first small protests, injuring dozens.
The president's fiery comments came two days after Russia announced a major bailout loan for Ukraine, which has been facing a possible default. Russian President Vladimir Putin's economic package for Ukraine includes a pledge to buy $15 billion worth of Ukrainian state bonds and a sharp discount on Russian natural gas for Ukrainian customers.
In Moscow, Putin insisted that the bailout was driven by a desire to help a neighbour that was in dire straits and wasn't aimed at breaking off Ukraine's ties with the EU.
"We have nothing to do with that whatsoever," Putin said.
Putin also rejected allegations that Russia could send its troops into Ukraine to annex the eastern, mostly Russian, part of the country and split it in two. The eastern region has been mostly against the anti-government protests in Kyiv.
"This is sheer nonsense," he said.
Commenting on the deal with Putin, Yanukovych signalled that Ukraine might now commit to some parts of the Moscow-led economic bloc called the Customs Union, even though protesters say that would put Ukraine back under Russia's yoke, just like in Soviet times.
Yanukovych also said talks will resume on joint Russian-Ukrainian operation of Ukraine's strategic pipeline system, which carries Russian natural gas to Europe.
"Ukraine must find such a model of relations with strategic partners which would be acceptable to everybody," Yanukovych said.
Analysts said, however, that such moves contradict the EU deal and would be rejected by the opposition.
"Let's just be absolutely clear, this is totally incompatible with existing agreements with the EU, and will not be taken as a further sign that the government is serious at all about European integration," said Tim Ash, an emerging markets analyst with Standard Bank in London.
The president's comments were likely to provoke anger from the protesters who have occupied central Kyiv for nearly a month.
Jailed former Prime Minister Yulia Tymoshenko, a top opposition leader, denounced Yanukovych's agreements with Moscow as state treason.
"On Dec. 17, 2013, Yanukovych annulled Ukraine as an independent entity," Tymoshenko said in a statement Thursday. The West views her jailing as politically motivated, but Yanukovych has resisted pressure to release her.
But even though the centre of the Ukrainian capital was blockaded by gigantic barricades, Yanukovych claimed the country's political crisis was drawing to a close.
"The fact that lawmakers have returned to parliament and that it has begun working is a sign that the political crisis is being overcome," Yanukovych said.
The opposition on Thursday lifted their blockade of parliament to pass a bill that would absolve opposition activists of criminal responsibility in the protests. Opposition leader Oleh Tyahnybok sought to portray Thursday's bill as a victory for the protesters, urging them to remain.
"We should keep on standing and putting pressure on the authorities and only then victory will be ours," he told thousands of protesters.
In his interview, Yanukovych ridiculed opposition leaders and said he would not tolerate any illegal attempts to seize power.
"These are political opportunists," Yanukovych said of the opposition leaders. "What are they selling? Oratory. They are covering up their actual helplessness, lack of professionalism and responsibility."
Some experts believe Yanukovych is hoping the protesters will disperse on their own, as he faces a threat of Western sanctions if he resorts to violence again.
But many protesters say they have no plans to go home while Yanukovych is still in power.
"Ukrainians will not accept this kind of sell-off," said protester Anatoly Sushchenya, 31.