President Biden is seeking a five-year extension with Russia on the only remaining treaty limiting the world’s two largest nuclear arsenals just days before it expires, said two senior U.S. officials.

At the same time, his administration is preparing to impose new costs on Russia pending a newly requested intelligence assessment of its recent activities. The officials said Biden is ruling out a “reset” in bilateral relations with Moscow as many U.S. presidents have done since the end of the Cold War.

“As we work with Russia, so, too, will we work to hold Russia accountable for their reckless and aggressive actions that we’ve seen in recent months and years,” said a senior U.S. official, who like others spoke on the condition of anonymity to discuss a sensitive security matter.

The decision to seek a five-year treaty extension, which Russia supports but the Biden administration hadn’t settled on until now, reflects the rapidly approaching deadline for Washington to renew the New START pact Feb. 5, the officials said.

Kremlin spokesman Dmitry Peskov said Friday that Russia “welcomes the political will” for a New START extension from the Biden administration, but needs more time to study the details of Washington’s proposal, adding that the previous conditions put forward by former president Donald Trump’s team “absolutely did not suit us.”

“Russia definitely favors the preservation of New START and its extension so as to buy some more time for proper negotiations,” Peskov said.

President Donald Trump tried to conclude a shorter extension with Moscow in the final months of his presidency, but he failed to reach an agreement after his nuclear envoy spent months trying to persuade China to join the accord before dropping that demand.

Letting the treaty expire would allow Moscow and Washington to deploy an unlimited number of nuclear-armed submarines, bombers and missiles in what many experts fear could spark a nuclear arms race and further exacerbate U.S.-Russia relations.

“New START is manifestly in the national security interest of the United States and makes even more sense when the relationship with Russia is adversarial,” the senior U.S. official said.

As the Biden administration informs Moscow of its terms for an extension, the president will order Director of National Intelligence Avril Haines to provide him a full intelligence assessment of Russia’s alleged interference in the 2020 election, use of chemical weapons against opposition leader Alexei Navalny and bounties on U.S. soldiers in Afghanistan, officials said.

Biden is also asking Haines for an assessment of the massive cyberattack on federal agencies and departments related to the SolarWinds software breach, which many analysts and government officials have blamed on Russia. The request for the intelligence assessments will go out this week, said the officials.

“We will use these assessments to inform our response to Russian aggression in the coming weeks,” another senior official said.

Biden’s plans for potential punitive actions toward Russia at the outset of the administration is unique among his recent predecessors, all of whom attempted to turn a new page with the Kremlin in the hopes of encouraging a more productive relationship.

“This will be the first post-Soviet U.S. administration that has not come into office vowing to forge a warmer relationship with Russia,” said Angela Stent, a senior intelligence official on Russia during the George W. Bush administration.

The skeptical posture follows four years of growing animus toward the Kremlin within the Democratic Party for its interference in the 2016 election against Democratic presidential nominee Hillary Clinton. Trump came into office seeking a rapprochement with Russia, but opposition from his party and congressional Democrats stymied that effort.

Biden’s nominee for secretary of state, Antony Blinken, told lawmakers Tuesday that sanctions passed by Congress to target Moscow will be “extremely helpful in being able to impose . . . costs and consequences” on Russia.

Blinken said New START, which restricts the number of deployed strategic nuclear warheads to 1,550 and deployed strategic delivery systems to 700, gives the United States “tremendous access to data and inspections” and is “certainly in the national interest to extend.”

Not all of Biden’s aides have supported the idea of a five-year extension for the treaty.

Victoria Nuland, a longtime Russia hawk whom Biden will nominate to be the No. 3 official at the State Department, wrote in Foreign Affairs over the summer that the United States should seek only a one- or two-year renewal in the hopes of retaining leverage over the Kremlin.

“Washington should not grant Moscow what it wants most: a free rollover of New START without any negotiations to address Russia’s recent investments in short- and medium-range nuclear weapons systems and new conventional weapons,” she wrote.

In responses to Biden’s decision to seek a five-year extension, Trump’s former special envoy for nuclear negotiations, Marshall Billingslea, criticized the move, saying it “shows stunning lack of negotiating skill.”

“Took just 24 hours for Biden team to squander most significant leverage we have over Russia,” he tweeted.

But U.S. officials noted that Billingslea himself tried to secure a shorter extension with his Russian counterpart, Deputy Foreign Minister Sergei Ryabkov, but failed to make a deal, leaving a critical agreement dangerously close to expiration.

“We’re aware that the last administration engaged in negotiations on an extension of a New START for months but was unable to come with an agreement,” the first senior U.S. official said. “We also understand there have been various proposals exchanged during those negations, but we’ve not seen anything to suggest that at any point an agreement on the terms that have been reported was in place.”

Arms control advocates have also opposed holding out for a shorter extension.

“There is no evidence that Russia is desperate to extend the treaty or that a shorter-term extension would make Russia more likely to negotiate a follow-on agreement,” said Daryl Kimball, executive director of the Arms Control Association.

“A straightforward five-year extension would provide the new president with an early win and positive momentum, help restore U.S. credibility on arms control issues, and create the potential for more ambitious steps to reduce the nuclear danger and move us closer to a world without nuclear weapons.”

U.S. officials said they hoped a quick renewal of New START could provide a foundation for new arms control arrangements, potentially including China.

“We believe it’s absolutely urgent for China to take on greater responsibility, transparency and restraint for its nuclear weapons arsenal,” the U.S. official said.

The Biden administration is not interested in holding an extension of New START hostage to China, however, the official said, especially given that Moscow’s arsenal “is at least 10 times the size of China’s.”

In October, Russia expressed a willingness to freeze its overall number of nuclear warheads during talks with Billingslea — a move Biden officials said was a “positive development” they hoped to build on, even though details on verification had not been hammered out.

The Biden administration’s ability to work with Russia on arms control while confronting it on a range of other issues will be tested almost immediately.

On Sunday, Biden’s national security adviser, Jake Sullivan, called for the immediate release of Navalny, the Russian opposition leader detained in Moscow. Navalny had just returned home after receiving medical treatment in Germany following a poisoning attack this summer. Russian authorities put out a warrant for his arrest, claiming he had violated the terms of a previous sentence related to embezzlement charges.

“Mr. Navalny should be immediately released, and the perpetrators of the outrageous attack on his life must be held accountable,” Sullivan wrote on Twitter. “The Kremlin’s attacks on Mr. Navalny are not just a violation of human rights, but an affront to the Russian people who want their voices heard.”

Isabelle Khurshudyan in Moscow contributed to this report.