Latvian President Raimonds Vejonis arrives at the White House before meetings with U.S. President Donald Trump and his Baltic counterparts April 3, 2018 in Washington, DC.

When President Donald Trump hosts the leaders of Latvia, Lithuania and Estonia at the White House on Tuesday, the principal topic will be the growing spectre of Russian aggression against NATO allies in Eastern Europe.

Another national security concern, however, is likely to cast a shadow over U.S. relations with one of the visiting countries: Latvia's apparent failure to curtail widespread money laundering and corruption in the nation's banking sector.

The scourge of financial crime in Latvia is not new, and its roots trace all the way back to Soviet-era state policies. But at a time when cybercrime and transnational criminal networks are top priorities for U.S. law enforcement, Latvia's struggles have gained new urgency. They've also touched Trump personally, in the form of a 2014 FBI inquiry into talks he and several of his employees held with Russian and Latvian businessmen about building a hotel in Latvia's capital, Riga.

The problems in Latvia's financial industry grew so dire in February that the Treasury Department took steps to cut off the nation's third largest bank, ABLV, from the U.S. financial system. Investigators had found evidence that money moving through the Latvian bank was helping to finance North Korea's ballistic missile program.

The bank denied the allegations, but a new rule proposed by the Treasury Department's Financial Crimes Enforcement Network was enough to cause ABLV to collapse. In mid-March, the privately held bank announced a "voluntary liquidation" after the European Central Bank refused to bail it out.

Latvia suffered yet another blow to its banking sector during the same February weekend that the European Central Bank suspended ABLV's activities. Ilmars Rimsevics, president of Latvia's central bank, was detained on corruption charges, accused by Latvian authorities of soliciting around $130,000 in bribes from an unidentified bank.

Rimsevics, the Latvian equivalent of the U.S. Federal Reserve chairman, denied the charges. Yet shortly after he was released on bail, a different Latvian bank leveled new allegations of bribe solicitation against him.

It was unclear Tuesday to what extent, if any, U.S. officials might use the visit of Latvian President Raimonds Vejonis to raise the sensitive subject of his nation's corruption woes.

A White House spokeswoman told CNBC that Latvia's banking and regulatory problems are not slated to be on Trump's agenda when he meets Tuesday with Vejonis, Estonian President Kersti Kaljulaid and Lithuanian President Dalia Grybauskaite.

A spokesman for the Treasury Department declined to comment, noting that the 60-day public comment period is still open for the department's proposed rule on ABLV.