European officials are seeking to act as intermediaries between Russia and the US in the hope of salvaging a cold war-era arms control treaty that Donald Trump has threatened to scrap.

However, the diplomats involved are not confident of success in the effort to save the 1987 Intermediate-range Nuclear Forces (INF) treaty. Although they have the support of senior officials in the US defence and state departments, they face opposition from the White House, particularly from the national security adviser, John Bolton.

Nor is it clear whether Moscow is interested in a deal. The collapse of the INF would leave the Russian military free to deploy short- and medium-range nuclear missiles along its borders with Nato in Europe, and in China.

It would be hard for the US to benefit militarily from the treaty’s demise, as it would need allied states to offer launch sites for its missiles if they were to be deployed within range of Russia and China – and it is far from clear what country would offer its territory and thus make itself a target.

Yet Trump’s abrupt declaration at a political rally in Nevada on 20 October that he was going to pull the US out of the treaty, without informing allies, has focused criticism on Washington rather than Moscow. European officials have asked for time to make a last-gasp attempt to rescue the treaty, which they see as a key pillar of arms control in Europe.

They have sought to persuade their American counterparts that US abrogation of the treaty – without giving Russia a final opportunity to come into compliance – could further undermine global support for the US, and allow Moscow to escape the full blame for the treaty’s breakdown.

“The US administration needs to take the Europeans with them,” a European diplomat said. “It’s important that if the agreement fails it is clear to everyone that it is the Russians’ fault. I think the administration gets this.”

Trump will meet Vladimir Putin and the G20 meeting in Buenos Aires at the end of this month, but it is not clear that the issue will be raised. Bolton told Putin when they met in Moscow in October that Trump had made up his mind to dump the treaty, which has kept nuclear missiles out of Europe for more than three decades.

The US has been accusing Russia of violating the treaty for more than four years, through the development and deployment of a new ground-launched medium-range missile. Nevertheless, Trump’s declaration of intent on October 20 to pull the US out of the treaty marked a sharp break in US policy, which until then had been to ratchet up pressure on Russia, in part by the US announcing plans to develop its own counterpart missile, to use as a bargaining chip.

The declaration took the defence and state departments by surprise. A cabinet-level meeting to discuss policy on the INF scheduled for 15 October was scrapped without explanation by Bolton, officials said.

Russia has denied its new weapon violates the INF restrictions banning nuclear missiles with ranges between 500 and 5,500km. It also accuses the US of breaking the treaty on the grounds that launchers for interceptors in the Aegis ground-based missile defence system in Romania and soon to be deployed in Poland, could be used for an offensive cruise missile.

John Bolton, Donald Trump’s national security adviser, scrapped an interagency meeting to discuss the treaty last month. Photograph: Yuri Kadobnov/AFP/Getty Images

Russia has so far not agreed to allow inspections of its new missile or suggested any compromise involving the Aegis missile-defence system. The US has also been uncompromising. In the last discussions between Washington and Moscow on the INF, in June, the US arms control ambassador, John Ordway, passed on a US demand for a freeze in Russian deployment of its new missile.

According to sources familiar with the Russian account of the talks, Ordway’s terms also included a requirement for Moscow to admit it had violated the treaty, a condition the Kremlin was almost certain to refuse.

The state department confirmed Ordway’s meeting with a Russian delegation, but declined to provide further details.

Under the terms of the treaty, it would take six months for a US withdrawal to take effect, from the date of Washington’s formal notification of its intention to withdraw. But in the month since Trump’s declaration in Nevada, no such notification has been made.

The under secretary of state for arms control and international security, Andrea Thompson, told journalists on Thursday that no decision on timing had been made and appeared to suggest the president had not yet made a final decision on withdrawal.

“We’re in the middle of the interagency process. I don’t want to get ahead of it. Know that everyone involved with this is all hands on deck and getting information so that the president has everything that he needs to make the next decision,” Thompson said. She added that the US was sharing intelligence with Nato allies to help build support for the US case on the INF.

“The bottom line is they support us. They ask for more information. Obviously, the intelligence is key on showing partners and allies the continued violations. And we’re talking through next steps, and that’s the important thing, that it’s a collaborative process whether it’s with Nato partners or here at home, that we’re getting input for next steps to make sure that there is no gap between us as – when the president makes his decision.”

A group of US, Russian and German nuclear weapons experts, known as the Deep Cuts commission issued a statement on Sunday, warning of the dangers of allowing the INF to break down, and arguing for another effort to negotiate a compromise.

“The repercussions of a collapse of the INF treaty would be tremendous: it could trigger a new arms race, significantly increase the risk of nuclear escalation, further undermine political relations between the United States, Russia and Europe,” the commission said.

“We believe the United States and Russia should exhaust all cooperative options to solve the INF treaty crisis instead of scrapping the treaty.”