MORRISTOWN, N.J. — New Jersey will stop doing business with gun manufacturers and retailers that fail to adopt policies that go beyond federal laws, like conducting expanded background checks, to stop guns from falling into the wrong hands, becoming the first state to take such stringent action against the firearms industry.

The state will also apply pressure on major financial institutions, seeking information from banks that do business with New Jersey about their relationships and policies involving gunmakers and sellers.

The state, which says it pays more than $1 billion in bank fees every year, could use the disclosure requirements to decide whether to continue doing business with financial firms.

New Jersey estimated that it has spent more than $70 million in recent years on firearms, supplies and ammunition for the State Police and other law enforcement agencies.

The measures, which were unveiled on Tuesday by Gov. Philip D. Murphy, a Democrat, represent a novel strategy after a spate of mass shootings and a lack of action in Washington around gun violence.

Several major banks have taken matters into their own hands, cutting off banking and credit card services to gun retailers and stopping the lending of money to manufacturers who do not abide by age limits and background checks.

Now New Jersey has essentially decided to make its own rules to restrict the flow of guns, and officials said they hoped it would encourage other liberal states to follow their lead.

Besides expanded background checks, the state will also not do business with retailers who do not adopt similar policies prohibiting firearm sales to those disqualified in New Jersey, which includes more stringent restrictions such as convictions involving domestic abuse, among other red flags.

Though New Jersey already has strict rules around background checks and people who are forbidden from buying guns in the state, Mr. Murphy is seeking to expand those rules nationwide.

Gunmakers and retailers seeking to sell to the state’s law enforcement agencies would have to abide by New Jersey’s policies even if they operate in states with less stringent gun laws.

“We have an urgent responsibility to do this,” Mr. Murphy said. “We cannot let taxpayers unwittingly pad the pockets of anyone whose business practices may make the jobs of law enforcement even more dangerous or put our residents in harms way.”

Mr. Murphy’s order applies to state troopers, prosecutor offices and local law enforcement agencies that make purchases through the state. It would not include other municipal police forces that buy firearms directly from manufacturers or retailers.

New Jersey buys firearms, ammunition and related products from retailers and manufacturers based in the state and elsewhere around the country. The executive order would cover future contracts and does not need legislative approval.

While the plan did not include many details, officials said that within the next 30 days the state would develop policies on gun sales that would likely be shaped by measures supported by gun control groups.

These include training retail workers to detect straw purchasers and requiring sellers to keep electronic records and perform background checks for private sellers for a small fee.

The state would require vendors and financial institutions that it does business with to adopt the policies to be eligible for future contracts. While the state’s efforts are aimed mostly at retailers, it will also pressure manufacturers not to do business with sellers who do not embrace the stronger gun sale polices.

Mr. Murphy’s action is likely to draw strong pushback from the gun industry and its allies, who have been swift to promise bans and boycotts of companies that have instituted policies aimed at the gun industry.

“That’s something that the governor’s office has to consider,” said Alex Roubian, the president of the New Jersey Second Amendment Society, referring to the possibility of a boycott of New Jersey by firearms manufacturers. “Because if they’re going to put police officers’ lives in danger because of politics, that’s on the governor, not on the gun industry.”

Supporters of gun rights said existing laws adequately governed gun sales.

“Federal law already requires retailers to conduct background checks on all sales,’’ said Amy Hunter, a spokeswoman for the National Rifle Association. “Any retailer illegally selling firearms is in violation of current law. We are confident the governor knows these facts, and we urge him to join the N.R.A. in seeking enforcement of existing laws.”

New Jersey’s action came on the same day that Congress began debating various gun control measures, including restricting high-capacity magazines, though it was unclear whether the Trump administration would lend its support.

Mr. Murphy and the governors of 11 other states, including New York and California, sent a letter on Tuesday to President Trump and Senator Mitch McConnell, the majority leader, demanding that they support universal background checks and so-called red flag laws to prevent people who pose a risk to themselves or others from buying firearms.

“Putting an end to the gun violence epidemic is not a Republican or Democratic issue, it is an American issue,’’ the letter said.

While New Jersey has some of the country’s strictest gun control laws, Mr. Murphy’s executive order seeks to take on an issue that the state, like other states with similar laws, struggles with — stemming the flow of illegal guns into New Jersey.

Citing a study by the Brady Campaign, a gun control organization, the governor’s office said about 5 percent of dealers across the country were responsible for providing 90 percent of the guns used in crimes.

New Jersey’s plan requires retailers to take steps that exceed federal standards to “prevent, detect and screen for the transfer of firearms to straw purchasers or firearm traffickers.”

The governor’s office said more specifically that sellers could ensure that the name on the method of payment matched the name of a buyer; that online orders were made by the eventual gun owner; and that buyers were limited to purchasing one firearm every 30 days.

Mr. Murphy’s plan would also seek to prevent the sale of firearms to “prohibited individuals,” which as defined by New Jersey is a broad list.

Aside from people with a history of mental illness and those convicted of crimes related to domestic abuse, it would also include people convicted of any violent crimes and drug dealing, as well as buyers on a terrorist watch list kept by the F.B.I.

New Jersey’s move could also be the first step toward pressing other Wall Street banks to reassess their relationship with the gun industry.

While Citigroup and Bank of America publicly distanced themselves from gun manufacturers last year, many other big firms did not follow suit, in part out of fear of a backlash from Trump administration regulators and conservative states.

New Jersey’s requirement that financial firms disclose their ties to gunmakers could provide the public with new and specific information that some firms have been reluctant to divulge.

Mr. Murphy is hoping that other states, particularly those with large law enforcement budgets like New York, will join his effort. Last year, Mr. Murphy and Gov. Andrew M. Cuomo of New York formed a States for Gun Safety coalition that now counts eight states and Puerto Rico as members.

Mr. Murphy, who has made gun control one of the core issues of his tenure, drew praise from national gun control advocacy groups for his initiative.

“With this executive order, Governor Murphy is blazing a new path for states that want gun manufacturers, retailers and financial institutions to take action to help end gun violence,” said John Feinblatt, president of Everytown for Gun Safety. “And we hope to see other governors quickly follow suit.”

Andrew Ross Sorkin contributed reporting.