A combination of two photos shows US President Donald Trump and Russian President Vladimir Putin as they arrive for the G20 leaders summit in Hamburg, Germany, July 7, 2017. [Photo/Agencies]

The legislation all but dashes Trump's hopes for warmer ties with Moscow as his administration is dogged by congressional and special counsel investigations into Russian meddling in the 2016 US presidential election to sway it in Trump's favor.

Russian President Vladimir Putin, who has repeatedly denied the conclusions of US intelligence agencies that Moscow interfered using cyber warfare methods, has threatened retaliation against the legislation.

The Senate backed the bill by a margin of 98-2 with strong support from Trump's fellow Republicans as well as Democrats.

The bill, which includes a provision that allows Congress to stop any effort by Trump to ease existing sanctions on Russia, will now be sent to the White House for Trump to sign into law or veto.

It is the first major foreign policy legislation approved by Congress under Trump, who has struggled to advance his domestic agenda despite Republicans controlling the Senate and House of Representatives. The strong bipartisan support for the bill was a sharp contrast to the bitter partisan rancor during debate over how to overhaul the US healthcare system.

If Trump chooses to veto it, the bill is expected to garner enough support in both chambers to override his veto and pass it into law. The sanctions measure has already passed the House of Representatives by 419 to three votes.

Republicans and Democrats have pushed for more sanctions partly as a response to the election allegations. Trump denies any collusion between his campaign and Moscow.

Senator John McCain, a leading congressional voice calling for a firm line against Russia, said before the vote: "The United States of America needs to send a strong message to Vladimir Putin and any other aggressor that we will not tolerate attacks on our democracy."

Putin said Moscow would only decide on how to retaliate once it had seen the final text of the proposed law.

The bill would affect a range of Russian industries and might further hurt the Russian economy, already weakened by 2014 sanctions imposed after Russia annexed Crimea from Ukraine.

Besides angering Moscow, the legislation has upset the European Union, which has said the new sanctions might affect its energy security and prompt it to act, too.