Sen. Joe Manchin, D-W.Va., wants federal regulators to ban Bitcoin.

The virtual currency and payment system "has allowed users to participate in illicit activity, while also being highly unstable and disruptive to our economy," Manchin wrote to regulators in a public letter released Wednesday.

Citing Bitcoin's appeal as a tool for black-market purchases and fraudulent transactions, Manchin urged regulators to join Thailand and China in banning the currency. Russia also outlawed the use of Bitcoin in early February, although this goes unmentioned in Manchin's letter.

"Our foreign counterparts have already understood the wide range of problems even with Bitcoin's legitimate uses — from its significant price fluctuations to its deflationary nature," Manchin said in the letter.

Manchin's proposal arrives in the midst of a rough week for Bitcoin. A major exchange for trading the currency, MtGox, shut down this week after major technical issues and what appears to have been a $365 million theft, according to an alleged internal document circulating on the Internet.