Nippon Steel Chief Executive Eiji Hashimoto says the top Japanese steelmaker is standing firm on its proposed $15 billion acquisition of U.S. Steel.

Even if losing domestic sources of primary steel does not seem like a national security threat today, it might tomorrow.

The companies argued in a lawsuit announced on Monday that Biden violated the Constitution by blocking the merger via a sham national security review that deprived the companies of their right to a fair process.