The chairman of the House Armed Services said Thursday the NATO alliance must be united and “push back” against Russia for its suspected role in a U.K. nerve agent attack and a range of other malign activities in the country.

The call for stronger action from Rep. Mac Thornberry came just as the Trump administration unveiled new sanctions against Moscow for its 2016 election interference and the U.S. joined France, Germany, and the U.K. in concluding Russia was likely behind the attack this month on a former spy and his daughter.