American Airlines pilots’ union plans to hold a vote next month on whether to allow members to call a strike as talks for a new labor contract continue.

The vote notice comes two days after American Airlines CEO Robert Isom said the carrier is prepared to raise pilot pay to match compensation at rival Delta Air Lines, whose pilots approved their new contract last week.

“While our Negotiating Committee reports good progress, we remain steadfast and focused that now is the time to reach an agreement with American Airlines,” the American Airlines pilots’ union said Thursday. “APA must also ensure it utilizes all its legal processes for contract resolution and improvement.”

Delta’s pilots are getting 34% raises in the new four-year deal, alongside other improvements. They had approved a strike authorization vote in the fall, about a month before reaching a preliminary deal with the company.

Even if American pilots’ union called a strike it would not be immediate; airline strikes are extremely rare in the U.S. and would follow a lengthy process involving federal mediators.

American didn’t immediately comment.