U.S. intelligence agencies tried to use vital medicines as leverage to recruit a Russian diplomat as a spy, Russia’s foreign ministry has alleged.

U.S. agents cornered a member of embassy staff as they tried to buy medicine for former Russian Prime Minister Yevgeny Primakov, Foreign Ministry Spokesperson Maria Zakharova claimed on Sunday.

Zakharova did not specify when the event took place, but Primakov died after a protracted illness on June 26, 2015.

Speaking on Russian state television, she said that the diplomat had been asked to buy medicine for Primakov which was only available in the United States. The politician’s family and friends had gathered the money needed to buy the drugs and all of the necessary permits and doctors’ certificates had been obtained in advance, she said.

Zakharova claimed that the diplomat was taken from the pharmacy to an unknown basement, where U.S. intelligence officers seized the medicine and accused them of exporting drugs illegally.

The diplomat was ultimately expelled from the United States, despite the intervention of Secretary of State John Kerry, Zakharova said.

The U.S. government finally delivered the drug to Primakov, but only after “a lot of wasted time,” she claimed.

Zakharova’s allegations come at a time of increasing tensions between U.S. and Russian security services. An unverified dossier published by the U.S. media last week claims that Russia’s intelligence agencies had previously gathered “compromising information” on U.S. President-elect Donald Trump, including sexually explicit material.

Trump and the Kremlin deny all claims.

Yevgeny Primakov led the Russian government between 1998 and 1999, having previously served as foreign minister. He died in 2015, aged 85.