The Russian Foreign Ministry said on Friday it has ordered the US to cut its diplomatic staff to 455 as of September 1 to match the number of Russian diplomats in the US, in what seems like Moscow's response to a new round of US sanctions against it.

Such a reduction will lead to the expulsion of around 700 staff members, said the deputy speaker of the Russian parliament Sergei Zheleznyak.

The Russian ministry said it would also seize a dacha compound and a warehouse, both used by US diplomats, as of August 1.

Russian President Vladimir Putin (L) and US President Donald Trump  (R) shake hands during a bilateral meeting on the sidelines of the G20 summit in Hamburg, Germany. /VCG Photo

This move came a day after US Congress slapped new sanctions on Russia for its alleged interference in the 2016 presidential election. The bill, which was overwhelmingly passed by the Senate on Thursday night, also prevents the president from easing sanctions without the approval from the Congress. It puts Donald Trump in a tough position by forcing him to take a hard line on Moscow or veto the legislation and risk angering his own Republican Party.

Trump has yet to sign the sanctions bill into law.

Russian President Vladimir Putin had warned on Thursday that Russia had so far exercised restraint, but would have to retaliate against "boorish and unreasonable US behavior."

Russian President Vladimir Putin. /VCG Photo‍

The Russian Foreign Ministry also warned the US it would respond in kind if Washington decided to expel any Russian diplomats.

The US ambassador to Russia John Tefft expressed his strong disappointment and protest. The Russian government's notification has been passed on to Washington, a US embassy spokesperson said.