What awaits the Cygnus spacecraft when the US runs out of Russian RD-181 engines

The Cygnus cargo spacecraft is scheduled to fly to the ISS in August. But the planning of this flight is

this moment remains unclear due to the fact that the United States may not have Russian RD-181 rocket engines left. Discuss

And it's not just the sanctions. The first stage of the Antares medium rocket, carrying a cargo ship and containing two RD-181s, is produced in Ukraine.

Since the beginning of the special operation, the availability of components for assembling the stage and engines has been a big question.