US is against the Nord Stream 2 pipeline because America wants to destroy Europe, as one of its main economic competitors. The destruction of Europe is going to happen through the increase in the energy prices, to make its economy uncompetitive, and by ripping UK out from Europe.
Recurring pro-Kremlin disinformation narrative about the US presence in Europe.
The US Congress has been opposing the construction of the Nord Stream 2 pipeline in Europe as a threat to energy and national security of European allies. Such position is shared by the European Parliament as well.