A draft proposal put forth last week would ban loud music, women and men mingling in public, billiards, and more.
The focus of the 24th Marine Expeditionary Unit is largely security, but will include humanitarian work.
Democrats say an overemphasis on the war in Iraq has come at the expense of Afghanistan and has allowed Al Qaeda to regroup in that region.
Talks began in 2007, a powerful coalition revealed last week. Experts say the move, an effort to undercut the government, could draw Taliban into the political process.
At the NATO meeting in Romania Thursday, Afghan officials are expected to request money to expand its National Army from 86,000 to 120,000 troops.