A total of more than 20 countries have agreed to participate in the new U.S.-led coalition safeguarding commercial traffic in the Red Sea from attacks by Yemen’s Houthi movement as more nations join the effort, the Pentagon said on Thursday.

Still, the new Pentagon total would suggest that at least eight of the countries who have signed up have also declined to be publicly named, in a sign of political sensitivities of the operation as regional tensions soar over the Israel-Hamas war.

“We’ve had over 20 nations now sign on to participate,” Major General Patrick Ryder said, noting declarations by Greece and Australia.

“We’ll allow other countries, defer to them to talk about their participation.”