“The White House said that the bill could be toughened, so it doesn’t change the essence of the situation,” Mr. Peskov said.
It is unclear whether Mr. Trump will sign the legislation. Given the congressional investigations into possible collusion between his campaign and the Kremlin, and considering that the Republican Party has majorities in the House and the Senate, he is under considerable pressure not to use his veto.
But the White House has been ambivalent about whether Mr. Trump will give his approval. During his campaign for the presidency, Mr. Trump pledged to improve ties with Russia.
The United States Embassy in Moscow issued a short statement confirming only that it had received the notification from the Russian Foreign Ministry and that it was sending the orders to Washington for review. The American ambassador, John F. Tefft, expressed “his strong disappointment and protest,” the statement said.
The statement from the Russian Foreign Ministry said that the United States Embassy was asked to reduce its diplomatic and technical staff members in Russia to 455 by Sept. 1, matching the number of Russian diplomats in the United States.
In addition to the main embassy in Moscow, the United States maintains consulates in St. Petersburg, Yekaterinburg and Vladivostok.
It was not immediately clear how many American workers would have to leave, because the Kremlin’s announcement did not detail which employees were to be included in the count. There are hundreds of staff members in Russia, including workers constructing an embassy building in Moscow.
Starting on Aug. 1, Russia will also block access to a warehouse in Moscow, as well as to a bucolic site along the Moscow River where staff members walk their dogs and hold barbecues.
In December, President Barack Obama expelled 35 Russian diplomats and seized two estates, one on Long Island, N.Y., and one on Chesapeake Bay in Maryland, in response to Russia’s meddling in the United States presidential election.
Moscow did not respond at that time, with President Vladimir V. Putin signaling that he was hoping for better relations under the future President Trump. Those hopes have largely evaporated.
On Thursday, while expressing annoyance, Mr. Putin said at a news conference in Finland that he would wait to see the final law on the new American sanctions before deciding on a response. But the Senate vote tipped the balance, Mr. Peskov said.
The announcement from the Russian Foreign Ministry said that if the United States responded to the latest measure with any further expulsions, Russia would match them.
The White House has lobbied against the law containing the extra measures, calling it a curb on presidential power, because it would effectively force Mr. Trump to seek congressional approval before lifting any sanctions. The fact that it passed a Republican-controlled Congress underscores the unease in Mr. Trump’s own party about his repeated praise of Mr. Putin and of Russia.
The new law would strengthen sanctions first directed against Russia in 2014 after the annexation of Crimea and the destabilizing of Ukraine. Those sanctions curbed American involvement in the oil industry and limited Russian access to Western financial markets. Russia responded with a broad ban on Western food imports.
The new legislation would expand some of the measures, particularly in the energy market. Various European nations have expressed concern about the law’s potential impact on the energy market on the Continent, because it might affect the expansion of the Nord Stream pipeline that carries Russian natural gas to Germany under the Baltic Sea.