It happened before.
The US administration "hired" its most trusted lapdogs (Poland and Baltics) to bark against Nord Stream.
But as you know they have failed, because Germany needed it badly.
Polish Foreign Minister slams Nord Stream pipeline :: The Baltic Course | Baltic States news & analytics
Russia accuses Estonia of "crude politicization" over Nord Stream
Analysis: Estonia will not allow the Nord Stream pipeline on its seabed | Moldova.org
Diplomaatia – Nord Stream: Estonia’s Lost Battle
This time Germany is pretty much safe, so it could play along with Washington to prevent the South Stream from happening.