(AFP) - The United States announced sanctions and the expulsion of 10 Russian diplomats Thursday in retaliation for what Washington says is the Kremlin's US election interference, a massive cyberattack and other hostile activity.

President Joe Biden's broadside against Russia came the same week as he offered to meet President Vladimir Putin for their first summit -- an idea he reiterated in a speech Thursday, explaining that despite the sanctions it was now "time to deescalate."

Washington is "not looking to kick off a cycle of escalation and conflict with Russia," Biden said, calling the sanctions "proportionate."

In his executive order, the Democratic president widened restrictions on US banks trading in Russian government debt, expelled 10 diplomats who include alleged spies, and sanctioned 32 individuals accused of meddling in the 2020 presidential election.

Biden's order "sends a signal that the United States will impose costs in a strategic and economically impactful manner on Russia if it continues or escalates its destabilizing international action," the White House said in a statement.

The Kremlin said Thursday that sanctions would not "help" momentum for a summit and the Russian foreign ministry warned a Russian riposte was "inevitable."

The latest tension comes against a backdrop of long-term anger in Washington at Russian election meddling and worries both in the United States and its European allies over Russia's recent troop build-up on the border of Ukraine.

The almost fatal poisoning and ongoing imprisonment of Alexei Navalny, who is effectively the last open political opponent to Putin, has further spiked concerns in the West.

A senior US official, who spoke on condition of anonymity, told reporters that Washington was ready to impose more measures if necessary and also that additional actions are already in place but "will remain unseen."

Despite this, Biden stressed he wanted to work with Russia and that a summit could allow them to "launch a strategic stability dialogue" on a host of global issues, ranging from Covid-19 to Iran's nuclear program.

On Ukraine, however, Biden said he'd "strongly urged" Putin "to refrain from any military action" and he "affirmed US support for the sovereignty and territorial integrity of Ukraine."

After Donald Trump's mixed signals to Russia -- and accusations that the Republican even seemed intent on shielding Putin from criticism -- the Democratic chair of the Senate foreign relations committee cheered Biden's approach.

"It is reassuring and frankly a relief to have a president willing to clearly call Putin what he is -- a killer, a military aggressor in Ukraine, a source of malign influence, a cyber threat," Senator Bob Menendez said.

- Allies back up US -

The sanctions are designed to hurt Russia's economy by making it harder to raise money on international markets. Starting June 14, US banks will be barred from buying government bonds directly from the Russian central bank, the finance ministry or sovereign wealth fund.

The White House statement explaining its actions listed in first place Moscow's "efforts to undermine the conduct of free and fair democratic elections and democratic institutions in the United States and its allies and partners."

This referred to allegations that Russian intelligence agencies mounted persistent disinformation and dirty tricks campaigns during the 2016 and 2020 presidential elections, in part to help Trump's candidacies.

The White House said the sanctions likewise respond to "malicious cyber activities against the United States and its allies," referring to the massive so-called SolarWinds hack of US government computer systems last year.

For the first time, the US government named the Russian foreign intelligence service, the SVR, as the organizer of the attack. The SVR called the accusation "nonsense."

The White House statement also called out Russia's "targeting" of dissidents and journalists on foreign soil.

In addition, the Department of Treasury, together with Australia, Britain and Canada, sanctioned eight individuals and entities associated with Russia's occupation of Crimea in Ukraine.

US allies responded with a carefully choreographed show of support.

In Brussels, the NATO military alliance said US allies "support and stand in solidarity with the United States" against Russia's "sustained" hostility.

The European Union also issued a statement expressing "solidarity with the United States on the impact of malicious cyber activities."

The US ambassador to Russia, John Sullivan, said that at a "professional and respectful" meeting at the foreign ministry in Moscow he told officials of Washington's intention to hold the government "accountable for its adversarial actions."

Britain's Foreign Office said it had summoned the Russian ambassador to complain about Moscow's "malign activity."

© Agence France-Presse