April 21 (UPI) -- Russian President Vladimir Putin said in his annual state of the nation address on Wednesday that any country that threatens Russia will regret it "in a way they've never regretted anything before."
Putin's warning comes amid growing tensions between the United States and Russia. Last week, President Joe Biden's administration imposed stiff economic sanctions against Moscow for interfering in the 2020 U.S. presidential election and for the SolarWinds cyberattack last year that targeted government and private computer networks.
There are also tensions between the two nations related to prominent Kremlin critic Alexei Navalny, who was poisoned last year and is now in a Russian jail. This week, he was transferred to a correctional hospital with severe illness. Nationwide protests in Russia supporting Navalny are planned Wednesday.
Russia also continues to mount a troop buildup along its border with Ukraine. In a call with Putin last week, Biden said the United States is concerned about the military moves.
"I hope no one will think of crossing so-called 'red lines' against Russia, which we ourselves will define in each separate case," Putin said in his speech Wednesday. He did not specify what constitutes the "red lines."
"We don't want to burn bridges, but when someone views our good intentions as indifference or weakness and intends to blow up these bridges, in turn, they must know Russia's response will be asymmetrical, swift and harsh."
"Anyone who stages any provocations that threaten our safety will regret it in a way they've never regretted anything before," he added.
Putin started his speech by focusing on the COVID-19 pandemic and urged Russians to get vaccinated.
"This will allow the formation of herd immunity by the fall. There's no other way to defeat the pandemic."
Putin said the global health crisis has caused economic hardships in Russia.
"We are faced with rising prices. It is impossible to rely only on targeted, directive measures. This leads to empty shelves, as was the case in the late 1980s," he said. "Now, even at the peak of the epidemic, we did not allow this. With the help of market mechanisms, it is necessary to ensure price containment."
He urged the government to take measures to help low-income families with children by July.
"In Russia, single-parent families will receive a payment of 5,650 rubles ($73) for each child from 8 to 16 years old," he said.
Putin proposed a monthly payment of 6,000 rubles ($78) to "help women who are expecting a baby and are experiencing financial difficulties" and said families with school children will receive 10,000 rubles ($130) per child.