The state of Texas has denied a request to have Russian officials be present at polling stations during the Nov. 8 general election, according to a letter obtained by NBC Dallas-Fort Worth.

The Texas secretary of state's office said it received a letter from Russia's consulate general in Houston seeking to have one of its officers present at a voting precinct to study the "US experience in organization of voting process."

Texas Secretary of State Carlos Cascos said no, adding that "only persons authorized by law may be inside of a polling location during voting. All other persons are not authorized and would be committing a class C Misdemeanor crime by entering."

Similar requests from Alexander Zakharov, Russia's consul general in Houston, were sent to officials in Oklahoma and Louisiana.

Republican presidential nominee Donald Trump has faced criticism for suggesting the election might be "rigged," and the U.S. earlier this month accused Russia of coordinating the theft and disclosure of emails from the Democratic National Committee and other institutions and individuals in the U.S. to influence the outcome of the election.

Thousands of hacked emails from accounts of individuals within Democratic nominee Hillary Clinton's campaign have been posted on the website of the WikiLeaks organization. Russian officials have denied their involvement in the cyberattacks.

While there is a formal process for foreign governments to observe U.S. elections, individual states maintain the authority to approve or deny those requests, said U.S. State Department spokesman Mark Toner.

"Any suggestion that we rejected Russia's proposal to observe our elections is false," Toner said in a statement. "Individual parties – foreign governments, NGOs, etc. – are welcome to apply to state governments to observe our elections."

Russia hasn't participated in an international mission to observe elections, so its effort to do so on the state level represents "nothing more than a PR stunt," Toner said.

White House Press Secretary Josh Earnest said the purpose of the requests was uncertain. He added it was "appropriate" that people might be suspicious of Russia's motives.

Zakharov's letter to state election officials was dated Sept. 24, but Oklahoma and Texas officials said they received it in late August.

Zakharov's office did not return a message from The Associated Press inquiring about the discrepancy, and a request for comment from the Russian Embassy in Washington was not immediately answered.

Sean Murphy, of The Associated Press, contributed to this report.