LONDON, U.K.: Shopify will ban all vape sales on its platform as early as this week, following pressure from a bipartisan group of U.S. state attorneys general seeking to curb online sales of illegal e-cigarettes, according to two sources familiar with the plans.

The move would make Shopify one of the most prominent e-commerce platforms to cut off an industry that U.S. regulators say has been flooded by unauthorized products, many of them imported from China.

Shopify, based in Ottawa, provides the infrastructure that millions of merchants use to operate online stores. It has been in discussions since last year with a coalition of 25 state attorneys general, who have urged the company to take stronger action against vapes that lack the legally required authorization for sale in the United States or otherwise violate the law.

"We've always prohibited illegal activity and take action when we become aware of merchants violating our policies," a Shopify spokesperson said in a statement, adding such internal decisions take into account global legal frameworks and are not based on feedback from any one group.

"We adjust our enforcement approach when legal changes call for it," the spokesperson said.

The ban is expected to apply to all vape products in the United States, including those authorized by the U.S. Food and Drug Administration, the sources said. It was not immediately clear whether the restriction would extend to other countries. Shopify did not answer a question on its geographic scope.

The expected ban could disrupt e-commerce sales and have a "chilling effect" on sellers, one of the sources said.

Illegal vapes are widely available in the United States through online stores, vape shops, convenience stores, and gas stations, despite being illegal to import or sell. British American Tobacco estimates the illegal U.S. vape market is worth about $9 billion.

The FDA has authorized only 45 e-cigarette products, most of them tobacco-flavored. Big tobacco companies, including British American Tobacco, argue that the limited number of authorized products has stifled the legal market and helped illegal sellers thrive.

E-commerce accounts for a relatively small share of authorized vape sales, so the Shopify ban is expected to have a limited impact on licensed companies such as British American Tobacco and Juul, one source said. Online sales are a more important channel for illegal vape sellers, although most unauthorized products are still sold in physical stores.

The crackdown has also reached payment companies. Mastercard warned partners responsible for adding merchants to its network in a May notice that unlicensed vape sales violate its standards.

Mastercard said those partners are "attesting that all appropriate controls are in place" when registering merchants to ensure their activities comply with the law. It recommended reviewing product inventories and monitoring transactions and invoices.

"We have zero tolerance for unlawful activity on our network," Mastercard said.