At his annual news conference, Putin also mocked his most visible critic, Alexei Navalny, saying that those like the opposition leader want to drive Russia into chaos ahead of the March 18 presidential election in Russia.
Brimming with self-confidence during the nearly four-hour session, Putin reaffirmed his denial of interference in the 2016 U.S. presidential election.
"All of it was invented by people who oppose President Trump to undermine his legitimacy," Putin said in remarks that mirrored Trump's arguments. "I'm puzzled by that. People who do it are inflicting damage to the country's domestic political situation, incapacitating the president and showing a lack of respect to voters who cast their ballots for him."
U.S. intelligence agencies have concluded that Russia interfered in the election to help Trump, a Republican, defeat Democrat Hillary Clinton. Trump last month lashed out at those agencies' former heads, calling them "political hacks" and arguing there were plenty of reasons to be suspicious of their findings.
Putin said Russian Ambassador Sergei Kislyak, whose contacts with Trump's campaign are part of the probes by Congress and special counsel Robert Mueller, was only performing his routine duties.
"It's a universally accepted practice when diplomatic envoys and even government officials meet candidates and their teams to discuss some issues, prospects for development, trying to get an idea what they will do if they come to power and how to respond to that," Putin said. "What is extraordinary about it and why should it trigger some sort of spy mania?"
Putin also praised Trump's successes, saying that global markets have demonstrated investors' confidence in his economic course.
"We can objectively see quite serious achievements even during his short time in office," Putin said.
The Russian leader said he and Trump had spoken on a first-name basis on the sidelines of two international summits this year, and he voiced hope that Trump eventually would be able to fulfill his campaign promises to improve ties with Russia.
"I hope that he would gradually have opportunities to establish contacts with Russia," he added.
Putin emphasized the countries need to cooperate on tackling global challenges and that Russia is ready for "constructive" cooperation on tackling the North Korean standoff.
Putin has warned the U.S. not to use force against North Korea, adding that the consequences will be "catastrophic." He emphasized that Russia opposes Pyongyang's nuclear ambitions, but added the U.S. had "provoked" the North into developing its nuclear and missile programs.
Putin said Moscow was encouraged by U.S. Secretary of State Rex Tillerson's statement about readiness for talks with Pyongyang, hailing it as a "realistic" approach.
He pointed out, however, that the U.S. sanctions against Russia have put Moscow on a par with Iran and North Korea. He said it looks "weird" in view of the fact that Washington expects Moscow's cooperation in tackling the North Korean crisis.
"It's beyond reason," he said.
The Russian leader also voiced concern about the U.S. considering a pullout from key nuclear arms control pacts.
He insisted that Russia has observed the 1987 INF Treaty banning intermediate range missiles and charged that the U.S. claims of alleged Russian violations are part of a "propaganda" campaign to pave the way for the U.S. withdrawal. He also blamed the U.S. for violating the pact, a claim that Washington has denied.
Putin also said that Russia wants to keep the 2010 New Start Treaty, which limited the U.S. and Russian nuclear arsenals to no more than 1,550 deployed nuclear warheads for each country. The treaty is set to expire in 2021, but the parties could agree to extend it.
Putin noted that some in the U.S. want to do away with the treaty and warned that "it would be very bad for international stability and security."
He emphasized that Russia will "ensure its security without entering an arms race," noting that Moscow's military spending next year will amount to some 2.8 trillion rubles (about $47 billion), compared with the Pentagon's budget of about $700 billion.
Putin, who announced his bid for re-election last week, said he would run as a self-nominated candidate, keeping his distance from the main Kremlin party, United Russia, which has many members dogged by accusations of corruption. A victory to another six-year term would put him on track to become the nation's longest-serving ruler since Soviet dictator Josef Stalin.
Answering a question from 36-year-old celebrity TV host Ksenia Sobchak, who wants to challenge him in the election, Putin said he doesn't fear competition but emphasized that the government would thwart any attempts by radicals to destabilize Russia.
Sticking to his habit of not mentioning Navalny by name, Putin likened him to Mikheil Saakashvili, a former president of Georgia who has turned into a Ukrainian opposition leader. Saakashvili has defied the Ukrainian government with a series of recent anti-corruption protests.
Putin said his government wouldn't let "people like Saakashvili" plunge Russia into the kind of instability that is now wracking Ukraine.
An embezzlement conviction that Navalny says is politically motivated bars him from running for president against Putin.
Navalny tweeted that Putin's statement "confirmed that not letting me run is a deliberate political move."
Most of the questions came from journalists from far-flung Russian provinces pushing various local projects, effectively serving as envoys for their regions.
Putin sought to burnish his image as a father of the nation who cares for the people's needs, alternating benign statements with his dry and sometimes harsh humor.
He backed his talk about the need for a strong military with a joke about a boy who swaps his father's navy dagger for a watch.
The youth is told by his father: "It's a good watch. When bandits will come to us and kill your mother and rape your older sister, you will come out and say: 'Good evening, it's 12:30 in Moscow.'"
Associated Press writer Nataliya Vasilyeva contributed.
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