Russia's deputy foreign minister on Wednesday acknowledged that detained US reporter Evan Gershkovich had not been granted consular access, two weeks after his arrest.
The Wall Street Journal journalist was arrested in Russia on claims of espionage, which he denies.
"The question (of consular access) is under review," Sergei Ryabkov was cited as saying by state-run agencies.
"We are acting in accordance with our laws, taking into account consular conventions of course," Ryabkov also said.
"We won't tolerate any attempts to put pressure" on Russia, he said.
The US State Department has said it has sought consular access to Gershkovich since learning of his arrest.
On Tuesday US President Joe Biden declared the imprisonment "illegal" after the State Department classified the reporter as "wrongfully detained".
Ryabkov said "for us, the status assigned in Washington does not matter."
Gershkovich's arrest is seen as a serious escalation of Moscow's crackdown on the media. His publication and officials also denied the charges against him.
Russia has classified his case as "secret", which limits the information available on it.