TOKYO (AP) — The last time the United States tried the military option on North Korea, more than a million died, a hostile and unexpectedly resilient adversary emerged and instead of regime change it got three generations of the Kim family. Understandably, there is little appetite in Washington to try that again. But if sending in the Marines is off the table, what's an administration to do?

A bill now making its way through the U.S. Congress — and being watched closely in Pyongyang — is designed to shut off the North, and anyone who deals with it, from the U.S. dollar.

Supporters say the tactic directly targets the wallets of North Korea's senior leaders. But opponents warn that over-politicizing the greenback might have more impact on its standing as the world's most influential reserve currency than on a country already largely excluded from international finance.

The House bill would block dollar-denominated trade or investment deals with North Korea as they pass through the U.S. controlled, dollar-based financial system.

The vast majority of all international financial transactions are denominated in dollars and nearly all of them are cleared through U.S.-based banks, which are regulated by the U.S. Treasury Department. That gives Washington its leverage.

The bill would punish North Korea's enablers by limiting their access to the dollar-based financial market, even on business that doesn't involve North Korea.

"By shutting down North Korea's illicit activities, we deprive the Kim regime of the money it needs to pay the generals and to conduct nuclear weapons research," House Foreign Affairs Committee Chairman Ed Royce, R-California, said after the act was introduced in February. He said the act, updated after the massive cyberattack on Sony Entertainment, would "step up the targeting of those financial institutions in Asia and beyond that are supporting this brutal and dangerous regime."

A sanctions bill is also planned in the Senate, but President Barack Obama's administration remains wary of new legislation that would make future negotiations with Pyongyang more difficult, or open up a new fight with China, which is where most of the potentially sanctionable banks would likely be.

Obama already has authority to take some action, and has used it. After pointing the finger at North Korea for the December cyberattack on Sony Pictures, he took executive action allowing the U.S. to sanction any entity, including a foreign bank, working with the North.

Treasury officials say their problem isn't the lack of power, but the dearth of targets.

North Korea has proven to be highly resilient and creative in the face of conventional sanctions. It is also accustomed to being deeply isolated from the global financial market.

Even so, the congressional action could be significant because it would provide even further incentive for foreign banks and multinational companies — which do need to remain in good standing within the international financial community — to avoid North Korea lest they face fines and litigation or are forced to freeze accounts and provide data to authorities about overseas operations and clients.

"The message is clear," Michelle Frasher, an expert on financial sanctions and a visiting scholar at the European Union Center of the University of Illinois, said in an email to The Associated Press. "If you want to do business here, you have obey U.S. laws and support U.S. interests, even abroad."

Pyongyang appears to be taking the threat seriously.

An editorial last week in the mouthpiece of the ruling Workers' Party slammed efforts in Washington to use the dollar as a weapon of coercive diplomacy. It referred to a statement by the U.S. Treasury secretary emphasizing the need for the U.S. to retain its leadership role in the International Monetary Fund as potential adversaries, and even some close U.S. allies, are beginning to back a potential rival organization being established in China.

"Many countries are rejecting with vigilance the U.S. using its currency as a lever for bringing down the social systems of other countries and realizing 'liberalization,'" the Rodong Sinmun editorial said. "The dollar has already lost its monopoly position as the world's key reserve currency."

"The U.S., the empire of dollars, is bound to go bankrupt," it said.

Pyongyang recently announced it will conduct trade in rubles with Moscow, sidestepping the dollar altogether. It is now engaging with the Asian affiliate of the Paris-based Financial Action Task Force on Money Laundering. North Korea remains one of just two countries on the influential body's blacklist — the other is Iran. Improved relations are key to building the country's credibility in the global financial world.

The weaponization of finance concept was tried out in 2005 with mixed results when Washington imposed sanctions against a Macau-based bank, Banco Delta Asia, which held about $25 million in North Korean funds. The sanctions cut Banco Delta Asia off from the international dollar-based financial system and almost caused it to collapse.

It was later lifted to facilitate nuclear talks, but the stigma it created turned North Korea into kryptonite for most banks, which continue to avoid transactions with the country even when they are not expressly banned.

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AP writer Matthew Pennington contributed to this report from Washington.