Russia's embassy in Washington, D.C. rejected a request to give details about chemical weapons in light of the Novichok poisoning of the Kremlin critic.
The two men are also wanted over the attempted murder of an ex-Russian spy in the English city of Salisbury.
Navalny was arrested on Sunday after he arrived in Moscow from Berlin, where he had been treated for Novichok poisoning
The opposition leader told Spanish paper El Pais: "Putin wants to be the czar of Russia. He doesn't like anyone who opposes him."
Queen Elizabeth II got back to work today with her first public royal engagement since before lockdown, but the 94-year-old did not wear a face mask.
Queen Elizabeth II and Prince William are touring the top-secret chemical weapons lab which identified Novichok as the nerve agent used in a "reckless act against the United Kingdom."
State Duma speaker Vyacheslav Volodin said foreign operators such as German intelligence agents may have poisoned the Kremlin critic.
Alexei Navalny has long been one of President Vladimir Putin's most prominent domestic critics, and a target of the Russian regime.
The Russian opposition figure is being treated at Berlin's Charite hospital where he has been transferred from the Siberian city of Omsk.
The suspected poisoning on the Russian opposition figure bears the hallmarks of the 2018 attack on Sergei Skripal and his daughter Yulia, and a Bulgarian arms maker, Der Spiegel reported.
In the wake of the nerve agent attack in Salisbury, England, an intelligence chief pledged to fight back.
Moscow has cast doubt over the relevance of the footage showing two Russian nationals visit the U.K., travel to Salisbury and leave during the attack.
Prosecutors in the U.K. are prepared to file an extradition request for two Russians they suspect carried out a nerve agent attack that killed one person and injured three others.
Police are combing thousands of hours of closed-circuit TV footage.
The Russian government previously accused British intelligence officials of carrying out the Skripal poisoning as a way to stir up anti-Moscow sentiment.
Reports suggest the 44-year-old and her partner handled a contaminated item.
The man and woman who fell ill in Amesbury were exposed to the same nerve agent that hospitalized a former Russian agent and his daughter.
The ex-Russian spy and his daughter were hit with an attack that used 50-100 grams of Novichok, the head of the OPCW has said.
Vladimir Uglev identified the poison that hospitalized former double agent Sergei Skripal as Novichok.
The man who may have invented the poison that took down Sergey Skripal has said he supports the British government's stance on Russia.
Sergei Skripal is "improving rapidly," while his daughter can now look forward to leaving hospital.
State Department spokeswoman Heather Nauert said Russia was like a beast with "long arms" and "lots of tentacles."