Norwegian's UK subsidiary has been given tentative approval by the US Department of Transportation for a foreign air carrier permit.
The Scandinavian budget airline says that, once finalised, the permit will allow Norwegian UK to operate "low-cost flights between the US and Europe".
Tentative DOT approval, served on 14 July, follows the European Commission's warnings earlier this month that failure to grant the application would prompt the EU to pursue formal arbitration under the open-skies agreement.
The DOT, In a document outlining its decision, says it has taken into account commitments made by Norwegian chief executive Bjorn Kjos "with respect to hiring and employment practices".
Norwegian UK secured its UK operating licence in November 2015 and, under previously disclosed plans, is to start services from London Gatwick to Singapore in September and to Argentina in February 2018.