Escalating tensions between the U.S. and Russia and the political hurdles President Trump faces at home are making it increasingly difficult for Trump to achieve his campaign goal of warmer relations between Washington and Moscow, according to political observers.

Trump’s decision last week to expel 60 Russian diplomats accused of secretly operating as intelligence officers prompted Russian President Vladimir Putin to eject 60 American diplomats from his own country, escalating tensions that have simmered under the surface for months.

Russian Foreign Minister Sergey Lavrov said Monday that relations are now worse than they were during the Cold War. And it may not get better anytime soon.

While Russia’s suspected role in poisoning an ex-spy living in the U.K. was the catalyst for the latest round of retaliation, Trump has come under increasing pressure at home and abroad to take tougher steps toward Moscow amid scrutiny of Russia’s aggression around the world. Trump has found his efforts to normalize ties with Moscow particularly difficult thanks to the special counsel’s investigation into his campaign’s alleged collusion with Russia.

Bradley Blakeman, a Republican strategist and former George W. Bush aide, said that for all of these reasons, Trump has little hope for stabilizing Russian relations “in the near future” due to the complexity of his legal situation at home.

“Things will get worse before they get better as long as [special counsel Robert] Mueller’s probe goes on,” Blakeman said. “The [president] must be careful in making any public statements because the press will tie anything he says to the investigation.”

Trump was subjected to fierce criticism on March 20 after the White House said he had a phone call with Russian President Vladimir Putin that did not include any mention of the March 4 nerve agent attack on Sergei Skripal, the former Russian spy in Salisbury. Not only did Trump congratulate Putin during the call on an election victory many observers described as a sham, but the president also omitted the Kremlin’s efforts to interfere in the 2016 election — an issue on which Trump is perpetually viewed as being too soft.

After the conversation, Trump told reporters he looked forward to the possibility of meeting Putin face-to-face soon to discuss an “arms race” that had garnered little attention to that point from the White House. Soon after, however, Trump toughened up on Russia after critics accused him of failing to stand with the U.K. in the wake of the Skripal poisoning.

Trump expelled the diplomats and closed Russia’s consulate in Seattle. And the White House staff scrambled on Monday to downplay reports that the president had invited Putin to visit the White House during last month’s phone call.

But even as the White House unveiled the harshest measures it had taken against Moscow to date, Trump’s team made sure to leave the door open for cooperation with Russia if Putin decided to meet his American counterpart in the middle.

“Our relationship with Russia is frankly up to the Russian government and up to [Russian President] Vladimir Putin,” White House spokesman Raj Shah said last week.

Ford O’Connell, a Republican strategist, said Trump likely aims to replicate the relative success he has had in improving relations with North Korea by maintaining a position in Russia that breaks with the status quo, even if doing so costs him the opportunity to take a victory lap on his latest moves.

“[Trump] would’ve been better served in the short term by trying to make the case that he is, in fact, being tough on Russia,” O’Connell said. “This is a situation where you see a president deciding not to run the same playbook over and over again.”

Since Trump careened from inviting Putin for a West Wing visit to kicking out dozens of his representatives, multiple outlets have reported that White House aides are sparring internally over how hard they should be on Russia and how they should present those positions publicly.

Trump had instructed staffers not to speak openly of the measures he had ordered against Russia, such as sanctions and diplomatic expulsions, according to an NBC News reportpublished Thursday. He reportedly aimed to avoid the appearance of having folded under pressure from domestic critics and the media over his public desire to strengthen ties between Washington and Moscow, even as his administration has moved further from Trump’s campaign promise to forge a better relationship with Russia.

On the now-infamous congratulatory phone call with Putin, Trump reportedly warned Putin against pursuing nuclear weapons capable of striking the U.S. with faster and more deadly force.

“If you want to have an arms race we can do that, but I’ll win,” Trump told Putin on the March 20 call, according to NBC.

A New York Times report published Friday suggested Trump’s aides are actually pushing him to get even tougher on Russia in the wake of Moscow’s decision to dismiss dozens of American diplomats and close a U.S. consulate in St. Petersburg.