Washington (CNN) President Donald Trump declared Tuesday on Twitter that "the facts" prove he's been tougher on Russia than his predecessor, President Barack Obama. They don't -- especially when it comes to punishing Russia for interfering in US elections.

That hasn't stopped the President from pushing that line or from seeming to suggest in a Wednesday tweet that Obama be investigated for unspecified "Dem crimes" and not doing anything about Russian meddling in the 2016 election.

"Question: If all of the Russian meddling took place during the Obama Administration, right up to January 20th, why aren't they the subject of the investigation?" Trump tweeted Wednesday morning. "Why didn't Obama do something about the meddling? Why aren't Dem crimes under investigation? Ask Jeff Sessions!"

Question: If all of the Russian meddling took place during the Obama Administration, right up to January 20th, why aren't they the subject of the investigation? Why didn't Obama do something about the meddling? Why aren't Dem crimes under investigation? Ask Jeff Sessions!

After the Friday indictment by special counsel Robert Mueller of 13 Russians and three Russian entities for an extensive effort to interfere with US elections, Trump went on the attack against Democrats, tweeting in a spectacular fashion. Among his Twitter tirades, the President railed that, "I have been much tougher on Russia than Obama, just look at the facts. Total Fake News!"

The facts tell a different story.

Trump, who has been consistently and openly admiring of Russian President Vladimir Putin, has yet to levy a single sanction to punish Russia for election interference, despite the fact that Congress almost unanimously passed legislation that took effect on January 29 requiring him to do so, and despite senior intelligence officials testifying that Russia is trying to disrupt the 2018 midterms.

Administration officials say the Jan. 29 date was not a deadline but a starting date for levying sanctions and that the process will take time. But as time goes by, Trump's failure to act raises questions among his critics.

Despite the consensus view of all US intelligence agencies that Russia did indeed interfere, and public affirmation of this from members of Trump's own Cabinet, the President persists in doubting Russia played a role at all, according to CNN reporting.

US officials on Wednesday tried to assuage concerns about the White House stance on Russia, telling reporters that the administration has taken "direct action" to address Moscow's election meddling under the Trump administration, including delivering a direct warning to Putin. "He has been warned," one senior administration official said.

The official declined to detail any specifics about the actions the administration is taking, citing concerns including the classified nature of some information. "There are different kinds of direct action," the official said.

This official and others stressed that the process is slow but underway. "These things take a lot of time," one official said. "We don't want to be sued. Once we are sued, the entire sanctions process unravels."

"We take this very seriously. This is a national security issue," the official added, asking for time and space to work. "I would hope that you would just give us a little bit of an indulgence to do some of these things behind the scenes."

The official said US warnings to Russia about the 2018 midterm elections have been stark. "We're sending very clear messages to the Russian government, at the highest levels, that if they continue to take the kinds of actions that we've seen, that the intelligence chiefs have been laying out, this will have an extraordinarily negative effect on our relationship and there will be consequences," the official said in a briefing with reporters.

None of those messages have been delivered publicly, but the senior official said Wednesday that in Moscow, "we are getting their attention. ... There is a great deal of anxiety in Moscow."

But last week, the administration had yet another chance to levy sanctions for Russian cyber activity and, so far, has chosen not to.

And although a series of officials told CNN there has been an ongoing "punitive review" to address past election meddling, it has yet to yield sanctions, though the officials said they are possible. That review, the officials added, began before Mueller's indictments.

The Wednesday briefing by the official reflected a key dynamic in the Trump administration's approach to Russia: The warnings to Moscow, the official said, have not necessarily come from Trump.

The official said the tougher messages have been delivered in direct comments between US and Russian officials. "They get the message when other professionals talk to them," the official said, adding that they have used "different channels" that are "actually much more effective."

Indeed, while the President himself seems unable to criticize Russia for meddling and unwilling to lead a fight to protect future elections, officials around him, more hawkish about Moscow than the President is, frequently call out Russia, with military officials in particular taking steps that are likely to make Moscow feel pressured.

The administration used its national security strategy to explicitly label Russia a "revisionist" foe that's seeking to change the status quo, and it recommended developing several new nuclear weapons to counter Russian activity.

The US recently began ramping up its presence in the Black Sea , which sits on Russia's doorstep, between Eastern Europe, the Caucasus and Western Asia. The increased American presence makes Russia feel threatened, US officials said, and may be why Moscow seems to do more dangerous intercepts of US surveillance aircraft in the area than in other places.

The Trump administration has asked to increase funding for the European Deterrence Initiative, an Obama program aimed at bolstering NATO's defenses against Russia, by almost $2 billion. The White House has also built on the Obama administration's support for the Ukrainian military by providing it with arms.

The administration has done "a whole lot of other things that people tend to forget about" to pressure Russia and hold it accountable, said State Department spokeswoman Heather Nauert.

But compared with the Obama administration, Trump is so far pulling punches when it comes to sanctions for election interference.

In the lead-up to the 2016 election, when officials became aware of Russian meddling, Obama personally warned Putin in September against doing so. That October, the US publicly accused Russia of stealing emails from the Democratic National Committee, among others. Administration officials briefed lawmakers, and sought help from Republican leadership in issuing statements challenging Russia.

After the election, in December 2016, Obama targeted Russia for its election interference, sanctioning three companies, four top intelligence officials and two Russian intelligence agencies, the military spy service called the GRU, and the FSB, the civilian spy agency formerly known as the KGB.

No sanctionable activity 'just yet'

Trump hasn't taken a single independent step to punish Russia for its election meddling that's been publicly visible, not even with the powers granted by a new law, the Countering America's Adversaries Through Sanctions Act. That law allows the administration to target Moscow's powerful elites and companies and countries that do business with blacklisted Russian military and intelligence entities.

"We don't have sanctionable activity just yet, but we are working every day to determine if there is something taking place," Nauert said Tuesday.

But CIA Director Mike Pompeo told the Senate Intelligence Committee that the CIA has already "seen Russian activity and intentions to have an impact on the next election cycle here." There has been no public action from the administration on the issue to date.

Democratic lawmakers point out that the White House itself highlighted another example of Russia's sanctionable activity under the new law just last week, when it issued a statement blaming the Russian military for the June 2017 cyberattack called NotPetya.

Calling it "the most destructive and costly cyber attack in history," the White House said last Thursday that the virus "quickly spread worldwide, causing billions of dollars in damage across Europe, Asia, and the Americas."

It's a case where sanctions under the new law's cyber provisions would certainly apply, according to Sen. Robert Menendez of New Jersey, the senior Democrat on the Senate Foreign Relations Committee. "I expect the imminent imposition of sanctions by the administration," Menendez said. He added that if they're not imposed, the White House statement rings "hollow."

Menendez pointed out in a February 13 interview with CNN's Wolf Blitzer that, "it has been more than six months since CAATSA was signed into law, and not one mandatory sanction has been imposed. It's inexcusable." Trump "continues to ignore congressional will with respect to the mandatory sanctions passed last year," Menendez said.

Nauert, along with White House spokeswoman Sarah Sanders, defended the administration's record. "The sum of our actions as it pertains to Russia ... is not CAATSA. We have done a lot more than just CAATSA," Nauert said.

JUST WATCHED Trump targets Obama in Twitter tirade Replay More Videos ... MUST WATCH Trump targets Obama in Twitter tirade 04:23

Sanders pointed to the fact that the Trump administration has continued measures begun under Obama, who on top of the December 2016 sanctions expelled 35 Russian diplomats and seized two Russian diplomatic compounds in the US. At the time, the Kremlin said it wouldn't retaliate but would wait until the Trump administration took power.

Trump, then president-elect, said it was time for the country to "move on" from the issue.

Since Trump took office, his administration has used existing sanctions to target Russians for human rights abuses in December 2017 under the Global Magnitsky Sanctions and for Moscow's annexation of Crimea in January 2018, when it sanctioned 21 individuals , nine entities and the senior leaders of two Ukrainian separatist groups.

After Russia retaliated against Obama's December 2016 expulsion of its diplomats by demanding the US reduce its embassy and consular staff by more than 700 people, Trump initially thanked Putin for helping him pare down staff levels, in what he later described as a joke. The Trump administration eventually seized Russian diplomatic facilities in San Francisco, New York and Washington.

"That is partly because of what they did in our 2016 elections," Nauert said.

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Sanders also highlighted Trump's request for funding to increase the size of the military, the fact that he has upheld Obama administration sanctions and his decision to provide arms to Ukraine as examples of the President being tougher on Russia than Obama.

And she hinted that some action might be coming. "He has done a number of things to put pressure on Russia and be tough on Russia," Sanders said. "Last week there was an incident that will be reported in the coming days."