American fashion giant Gap Inc. has joined the Pakistan Accord, marking a breakthrough in efforts to expand membership of the worker safety initiative.

The news was announced by parent organisation the International Accord in a post on LinkedIn Thursday. It comes after of months campaigning to encourage large American brands to sign on to the binding agreement.

The Pakistan Accord is the first effort to internationalise a landmark safety agreement established in Bangladesh after the deadly Rana Plaza factory collapse in 2013. But Gap was among a number of American companies that launched a separate safety initiative and remained apart from efforts to expand the Accord framework.”

Gap signing on is a big deal and will likely lead to more signatories from the United States,” Scott Nova, executive director of the Worker Rights Consortium said in a statement. “The pressure is now on Levi’s, Target, Urban Outfitters, and other US brands and retailers to sign.”

The Pakistan Accord launched late last year and now has 65 signatories covering 450 factories.

Learn more:

How to Avoid Another Rana Plaza

In the wake of 2013′s deadly factory collapse in Dhaka, more than 200 brands signed the Bangladesh Accord, a legally binding safety pact. As the agreement expands internationally, BoF unpacks why it’s widely viewed as fashion’s most effective safety campaign, how it can help brands address new sustainability regulations and what limitations remain.