Russian President Vladimir Putin has told reporters that the ouster of Ukrainian President Viktor Yanukovych amounted to an unconstitutional coup and that Russia would use "all means" to "defend" Ukrainians.

"My assessment is that it's unconstitutional overthrow and and armed seizure of power," Putin told the press, according to the translation on Russia Today. "No one has challenged that."

Putin then began talking about the truce signed on February 21, which would have kept Yanukovych in power, and said that the ousted Ukrainian complied with the opposition's demands. Protesters rejected the deal and, after two bloody days, Yanukovych fled.

"Then the power was seized," Putin said. "Are the current authorities legitimate? Part of parliament yes, but the rest no. There is only one legitimate president — from a legal point of view, it's Mr. Yanukovych is president."

Yanukovych made a similar argument last week from the southern Russian port city of Rostov-on-Don, where he is under Kremlin protection. Putin also said that Yanukovych does not have a political future.

"The legitimate president, Yanukovych, asked Russia to defend the lives and health of Ukrainians. So our major concern is the ... nationalists and radical extremists that are rampant on the streets of Kiev."

About 16,000 Russian troops have invaded the southern Ukrainian peninsula of Crimea. They have surrounded several Ukrainian army bases in the strategic Black Sea region and are urging the soldiers to give up their arms and pledge allegiance to pro-Kremlin authorities in the region.

"We do reserve the right to use all the means to defend these people," Putin asserted. "We believe and do believe that Ukraine ... is our fraternal nation."

Putin said that he reinforced the military facilities in Crimea because radicals were moving toward Crimea. He added that he hopes that the Kremlin "does not have to do that" in the east of the country.

"Even if I decide to use the armed forces, then it will be in line with international law because we received a request from a legitimate president," Putin said. "This meets our national interest. This is a humanitarian mission."

Putin said that Russia did not participate in the formation of "self-defense" forces in Crimea. Last week, pro-Russian gunman commandeered the Crimea parliament and the regional governmental building before Russian troops mobilized on the strategic Black Sea peninsula. Some of the Russian troops surrounding Ukrainian soldiers are still not acknowledging being Russian.

"We are not going to go to war with the Ukrainian people. But there is the Ukrainian army," Putin stated. "If we make this decision, we will make it for the people of Ukraine."

He also noted that if Ukraine fails to pay for February gas supplies from Russia, they will owe $2 billion to the Kremlin. Putin also said that if elections in Ukraine are held in conditions of "terror," then Russia will not recognize them.

He concluded that the regime change in Ukraine was "well prepared."