The Kremlin has issued a tight-lipped response to the resignation of US national security adviser Michael Flynn, as Russian MPs and state TV suggested he was the target of a smear campaign and that his departure was evidence of Russophobia.

“This is the internal business of the Americans, it is the internal business of President Trump’s administration. This is not our business,” Kremlin spokesman Dmitry Peskov told journalists. “We’ve said everything we want to say.”

Flynn resigned on Monday night after conceding that he had given “incomplete information” about the nature of phone calls with Sergei Kislyak, Russia’s ambassador to the US.

A flow of intelligence leaks has suggested Flynn secretly discussed sanctions with Kislyak and then tried to cover up the conversations. Peskov has previously denied that Flynn and Kislyak had discussed sanctions.

Flynn’s departure has been seen in Moscow as a blow to the incipient thaw in US-Russian relations.

The Russian MP Leonid Slutsky, head of the foreign affairs committee in the lower house of parliament, said the resignation was forced, “provocative” and a “negative signal for the mending of Russian-American dialogue”.

“In these conditions, the conclusion that comes to mind of course is that the target was Russian-American relations and the undermining of trust in the new American administration,” he was reported as saying.

The story was top news on Russian state television, which was also pushing the message that the Flynn-Kislyak calls were business-as-usual: “[Flynn] had had dozens [of] conversations with foreign representatives, a normal diplomatic practice that for liberal America has become wicked if it involves Russia,” said a news report on state channel Rossiya 24.

Moscow had seen Flynn, who once sat next to Putin at a gala dinner for state news channel RT, as an ally in the US. Konstantin Kosachyov, chairman of the foreign affairs committee in the upper house, said it was “premature to declare Michael Flynn a Russophile” but praised him for the fact that “unlike many other high-level Americans, he was at least open to dialogue, visited Moscow and, as it turned out, communicated with our ambassador in Washington”.

“But even openness to dialogue with the Russians is interpreted by hawks in Washington as a thought crime,” Kosachyov wrote on his Facebook page. “To drive a national security advisor to resign for contacts with the Russian ambassador, a normal diplomatic practice, isn’t even paranoia, but something immeasurably worse.

“Either Trump hasn’t acquired the independence he sought and is being subsequently [and not without success] driven into a corner, or Russophobia has already struck the new administration from top to bottom.”

Alexei Pushkov, a senator who was previously foreign affairs committee chairman in the lower house, tweeted: “The departure of M. Flynn is probably the earliest resignation of a president’s national security advisor in all of history. But the target isn’t Flynn but relations with Russia.

“The expulsion of Flynn was just the first attack. Now the target is Trump himself.”