Russian officials and lawmakers are sharply criticizing U.S. legislation that would impose new sanctions on Moscow and make it harder for President Donald Trump to ease or lift punitive measures.
The European Union also voiced concern on July 26, saying it is ready to take swift action if the legislation passed by the U.S. House of Representatives a day earlier ends up undermining EU energy security.
In Moscow, Deputy Foreign Minister Sergei Ryabkov said the House vote was a "step toward the destruction of prospects for the normalization of relations" between Washington and Moscow.
"We have said dozens of times that these actions will not be left without a response," state-run Russian news agency TASS quoted Ryabkov, the Foreign Ministry's point man for relations with the United States, as saying.
Ryabkov told the Interfax news agency the new sanctions are pushing Russia and the United States "into uncharted territory both in the political and diplomatic sense."
The bill, which would also impose new sanctions on Iran and North Korea, passed in a near-unanimous vote of 419-3 on July 25.
Russian President Vladimir Putin's spokesman said news of its passage was "very sad from the point of view of Russian-American relations and the prospects of their development."
The spokesman, Dmitry Peskov, said it was "no less discouraging from the point of view of international law and international trade relations."
It is not clear when the U.S. Senate will address the bill.
After initially indicating Trump would sign the bill, White House spokeswoman Sarah Huckabee Sanders said on July 25 that while "the president supports tough sanctions on North Korea, Iran, and Russia, the White House is reviewing the House legislation and awaits a final legislative package for the president’s desk."
If Trump rejects the bill, Congress could override his veto if there is enough support for the legislation.
meanwhile, Konstantin Kosachyov, chairman of the international affairs committee in Russia's upper parliament house, said the U.S. legislation would do further harm to relations and called for a response that would be "painful" for the United States.
Strong bipartisan support for the sanctions legislation adds to pressure on Trump, whose presidency has been clouded by allegations that Russia meddled in the election on his behalf.
The Justice Department and Congress are conducting separate investigations into Moscow's alleged interference and whether there was any collusion between Trump's campaign and Russia.
Trump repeatedly indicated during the campaign that he would seek to improve ties with Moscow, which have been badly damaged by Russia's seizure of the Crimean Peninsula and aggression in eastern Ukraine, where it supports separatists in a war that has killed more than 10,000 people since April 2014.
But relations have remained severely strained amid the multiple investigations into what the U.S. intelligence community says was an "influence campaign" of cyberattacks and propaganda ordered by Russian President Vladimir Putin in an attempt to help Trump and denigrate his Democratic rival on the November 8 ballot, Hillary Clinton.
The new sanctions would add to punitive measures, mostly targeting the Russian economy and associates of Putin, imposed by the administration of former President Barack Obama in response to Russia's interference in Ukraine.
Passage by such a large margin in the House indicates many lawmakers from both parties want to punish Russia for its alleged attempts to interfere in the U.S. election as well as its actions in Ukraine and in Syria, where it has given President Bashar al-Assad's forces crucial support in a war that has killed hundreds of thousands of people.
"It is well past time that we forcibly respond," said House Foreign Affairs Committee chairman Ed Royce, a Republican from California. "Left unchecked, Russia is sure to continue its aggression."
Republican House speaker Paul Ryan said the sanctions package "tightens the screws on our most dangerous adversaries in order to keep Americans safe."
Some members of Trump's Republican Party saw the bill as a mild rebuff of what one suggested was his excessive eagerness to improve relations with Russia.
Trump's "rhetoric toward the Russians has been far too accommodating and conciliatory up to this point," said Representative Charlie Dent, a Republican from Pennsylvania.
"Russian behavior has been atrocious," he said. "They deserve these enhanced sanctions. Relations with Russia will improve when Russian behavior changes and they start to fall back into the family of nations."
Under the bill, Trump would be required to send Congress a report explaining why he wants to suspend or terminate sanctions imposed on Russia. Lawmakers would then have 30 days to decide whether to allow him to act.
The bill has drawn criticism from European Union allies, who have warned it could end up penalizing European firms that work with Russia on joint energy projects like the Nord Stream 2 pipeline to carry natural gas from Russia to Europe under the Baltic Sea.
House leaders said that they had altered language in the bill to try to address those concerns, but the EU indicated on July 26 that it still was worried.
In a statement, the European Commission said that the wording of the bill endorsed by the House "demonstrates that a number of these concerns are being taken into account.
"It nevertheless foresees the imposition of sanctions on any company (including European) which contributes to the development, maintenance, modernization, or repair of energy export pipelines by the Russian Federation. Depending on its implementation, this could affect infrastructure transporting energy resources to Europe -- for instance, the maintenance and upgrade of pipelines in Russia that feed the Ukraine gas-transit system. It could also have an impact on projects crucial to the EU's diversification objectives, such as the Baltic Liquefied Natural Gas project," the statement said.
The bill "could have unintended unilateral effects that impact the EU's energy security interests. This is why the commission concluded today that if our concerns are not taken into account sufficiently, we stand ready to act appropriately within a matter of days," it quoted European Commission President Jean-Claude Juncker as saying. "America first cannot mean that Europe's interests come last."
The bill's sanctions on North Korea would bar ships owned by Pyongyang or by countries that refuse to comply with UN sanctions against North Korea from operating in American waters or docking at U.S. ports. Goods produced by North Korea's forced labor would be prohibited from entering the United States.
Iranian President Hassan Rohani said his country would respond if the United States enacts the bill.
The sanctions against Iran would impose mandatory penalties on people involved in Iran's ballistic-missile program and anyone who does business with them. The measure would designate the Islamic Revolutionary Guards Corps as a terrorist organization and enforce an arms embargo against Iran.
Iranian officials say the bill violates the 2015 nuclear deal between Iran and world powers under which Tehran curbed its nuclear activities in exchange for international sanctions relief.
"If the enemy steps over part of the agreement, we will do the same, and if they step over the entire deal, we will do the same, too," Rohani said at a cabinet meeting aired by state broadcaster IRIB on July 26.
With reporting by RFE/RL Correspondent Rikard Jozwiak in Brussels, TASS, Interfax, RIA, Reuters, AFP, and AP