WASHINGTON — Three American citizens imprisoned for years by China have been released and are returning to the United States, the White House said Wednesday, announcing a diplomatic agreement with Beijing in the final months of the Biden administration.

The three are Mark Swidan, Kai Li and John Leung, all of whom had been designated by the U.S. government as wrongfully detained by China. Swidan had been facing a death sentence on drug charges while Li and Leung were imprisoned on espionage charges.

“Soon they will return and be reunited with their families for the first time in many years,” the White House said in a statement.

The release comes just two months after China freed David Lin, a Christian pastor from California who had spent nearly 20 years behind bars after being convicted of contract fraud.

U.S.-China relations have been roiled for years over major disagreements between the world’s two largest economies on trade, human rights, the production of fentanyl precursors, security issues that include espionage and hacking, China’s aggressiveness toward Taiwan and its smaller neighbors in the South China Sea, and Beijing’s support for Russia’s military-industrial sector.

The release of Americans deemed wrongfully detained in China has been a top agenda item in each conversation between the U.S. and China, and Wednesday’s development suggests a willingness by Beijing to engage with the outgoing Democratic administration before Republican President-elect Donald Trump’s return to the White House in January.

Trump took significant actions against China on trade and diplomacy during his first term. He has pledged to continue those policies in his second term, leading to unease among many who fear that an all-out trade war will greatly affect the international economy and could spur potential Chinese military action against Taiwan.

Still, the two countries have maintained a dialogue that has included a partial restoration of military-to-military contacts. President Joe Biden and Chinese leader Xi Jinping met this month to discuss potential improvements.

In a separate but related move, the State Department on Wednesday lowered its travel warning to China to “level two,” advising U.S. citizens to “exercise increased caution” from the norm when traveling to the mainland. The alert had previously been at “level three,” telling Americans they should “reconsider travel” to China in part because of the “risk of wrongful detention” of Americans.

The new alert removes that wording but retains a warning that the Chinese government “arbitrarily enforces local laws, including exit bans on U.S. citizens and citizens of other countries, without fair and transparent process under the law.”