With the U.S. campaign of “maximum pressure” now over, Iran’s oil customers may be growing a little bolder.

Iranian crude remains subject to American sanctions and exports are still just a fraction of levels seen three years ago, before Donald Trump cracked down to cajole Tehran into renegotiating a nuclear pact. But as new president Joe Biden seeks to revive the existing accord, firms that monitor Iran’s output—Petro-Logistics SA, Kpler Ltd. and SVB International LLC—have seen it creep higher.

“The output and export increase is an anticipation of Biden’s softer approach toward Iran,” said Sara Vakhshouri, SVB’s founder and president.

The estimated gains—which remain preliminary—aren’t huge, ranging from about 30,000 to 50,000 barrels a day in January. That’s far short of the grandiose announcements by Iranian officials, who last week said exports have increased “dramatically” and could return to prior levels within two months.

The picture remains opaque as Iranian vessels generally switch off transponders that would reveal their location. And the ongoing difficulty for Tehran was illustrated this weekend when Indonesia seized an Iran-flagged vessel for illegally transferring oil to another ship.

Yet the incremental gains in shipments are adding up. Iranian exports are set to exceed 600,000 barrels a day for the first time since April, according to Petro-Logistics. Flows are up 45% since October, SVB estimates.

It’s not clear whether the extra cargoes are actually being sold to refiners, or simply moved in anticipation of later transactions.

“With Iranian exports going through numerous transshipments and other clandestine behavior, it’s difficult to tell if these extra volumes will be shipped to refiners or stored for quick delivery once sanctions are loosened,” said Daniel Gerber, chief executive officer of Geneva-based Petro-Logistics.

Chinese Buyers

But it could well be that, in the less hostile environment, “Chinese buyers are gaining confidence that they can get away with higher imports,” Gerber said. Flows to China appear to have picked up lately, according to a trader at an oil major in Asia who asked not to be identified.

Whether the trickle turns into a flood will depend entirely on a diplomatic breakthrough between Tehran and Washington, which newly appointed Secretary of State Antony Blinken says remains a “long way” off.