WASHINGTON/SAVONLINNA, Finland, July 27 (Reuters) - U.S. President Donald Trump could veto pending legislation that would slap new sanctions on Russia in order to push for a tougher deal, a top White House aide said on Thursday, as Moscow warned of retaliation if Washington pressed ahead with the measure.
The idea of Trump seeking to strengthen the sanctions drew skepticism given that the administration had spent weeks lobbying for a weaker bill.
The sanctions, which the U.S. House of Representatives has passed, have yet to be approved by the Senate or Trump.
Russian President Vladimir Putin, who has repeatedly denied U.S. allegations that Russia interfered with last year's U.S. presidential election, said Moscow would only decide on how to retaliate once it had seen the final text of the proposed law.
Besides angering Moscow, the proposed legislation has upset the European Union, which has said the new sanctions might affect its energy security and prompt it to act, too.
Trump's fellow Republicans as well as Democrats have pushed for more sanctions partly as a response to U.S. intelligence agencies' findings of Kremlin interference in the election campaign.
The bill would affect a range of Russian industries and might further hurt the Russian economy, already weakened by 2014 sanctions imposed after the Ukraine crisis.
On Wednesday, U.S. lawmakers reached an agreement that cleared the way for the Senate to pass the measure as soon as this week. If passed, the bill would be sent to the White House for Trump to sign or veto.
The bill, if approved, threatens to further derail U.S.-Russian relations. Trump had hoped to improve ties but his administration has been clouded by U.S. investigations of Russian meddling in the November election to sway the vote in Trump's favor. Trump denies any collusion between his campaign and Moscow.
Trump's concerns include a provision letting Congress stop any effort to ease existing sanctions on Russia. But White House Communications Director Anthony Scaramucci suggested Trump in fact wanted stronger sanctions.
"He may sign the sanctions exactly the way they are or he may veto the sanctions and negotiate an even tougher deal against the Russians," Scaramucci told CNN.
The White House has said Trump is still evaluating the bill and supported strong sanctions against Russia. However, Trump can impose new sanctions at any time through an executive order.
"This bill doesnt preclude him from issuing tougher sanctions. That doesnt make any sense," said Edward Fishman, a former State Department official during the Obama administration who worked on U.S. sanctions policy.
BOORISH AND UNREASONABLE
"As you know, we are exercising restraint and patience, but at some moment we'll have to retaliate. It's impossible to endlessly tolerate this boorishness towards our country," Putin said in Finland on Thursday.
"When will our response follow? What will it be? That will depend on the final version of the draft law which is now being debated in the U.S. Senate," he told a joint news conference with his Finnish counterpart, Sauli Niinisto.
Putin also spoke about a continuing row between Moscow and Washington which erupted last December when then U.S. President Barack Obama ordered the seizure of Russian diplomatic property in the United States and the expulsion of 35 Russian diplomats.
"This goes beyond all reasonable bounds," said Putin. "And now these sanctions - they are also absolutely unlawful from the point of view of international law."
The White House's rhetoric on the sanctions bill echoes that surrounding the president's controversial decision to withdraw the United States from the Paris Climate Agreement, which includes 194 countries.
On May 31, Trump said the United States would no longer participate in the landmark 2015 global climate change agreement and that his administration would begin negotiations either to re-enter the Paris accord or to have a new agreement "on terms that are fair to the United States".
But other world leaders said a new agreement was not an option. French President Emmanuel Macron told Trump the deal could not be renegotiated. (Additional reporting by Susan Heavey, Eric Walsh, Rick Cowan, Valerie Volcovici, Roberta Rampton, Arshad Mohammed and Yeganeh Torbati in Washington; Writing by Yara Bayoumy; Editing by James Dalgleish)