Russia liquidated nearly all of its holdings of U.S. Treasury securities in just two months leading up to President Vladimir Putin's summit with U.S. counterpart Donald Trump, the Treasury's latest report shows.

Previously one of the top holders of U.S. debt, the Russian government shed 84 percent of its Treasury securities between March and May, dropping its holdings to $14.9 billion from $96.1 billion, according to the U.S. Treasury Department report published July 18.

The report was made public amid the furor over Trump's meeting with Putin on July 16, as Russia quietly dropped off the list of top Treasurys holders, falling below minor holders including Colombia and Kazakhstan.

Even before the sell-off, China and Japan both owned more U.S. debt than Russia, holding more than $1 trillion each in Treasurys.

Russia's move coincided with a Treasury note yield spike in mid-May that put them at a seven-year high of 3.11 percent. However, the 10-year yield quickly retreated below 3 percent, indicating the Russian sell-off had little impact on U.S. cost of borrowing.

Analysts have given various reasons for the possible move by Russia, some suggesting it may have been in part a reaction to U.S. sanctions and partly a portfolio adjustment.

"While this liquidation by the Russians is curious, the amount they held, along with the amount they sold, is really insignificant to the multitrillion-dollar Treasury market," Kevin Giddis, head of fixed income capital markets at Raymond James, told CNBC on Sunday.

"If I had to wager, I would bet that this is part sanctions and part portfolio adjustment and little to do with a real market move," he said.

In April, a fresh round of U.S. sanctions targeted 24 Russian oligarchs and 12 related firms amid accusations that the Russian government engaged in "worldwide malign activity," including meddling in the 2016 U.S. election.

"If this was China or Japan, then the story would be quite different, and so the muted market movement, or lack thereof, pretty much tells the story of the move," Giddis added.

Major foreign holders of U.S. debt account for $6.21 trillion of the $21.3 trillion total public debt as of July 26.