In the wake of Donald Trump’s reported comments that he would only defend the Baltic nations from a Russian invasion after evaluating whether “they fulfill their obligations to us,” NATO’s secretary-general and several Estonian officials hit back early Thursday at the Republican presidential nominee. “Solidarity among allies is a key value for NATO. This is good for European security and good for U.S. security,” Secretary-General Jens Stoltenberg told BuzzFeed News. “We defend one another.” The NATO treaty requires that its 28 members provide military aid in the event of an attack. Stoltenberg said he didn’t want to “interfere” with the U.S. election but that “two world wars have shown that peace in Europe is also important for the security of the United States.” After Trump’s comments were published in The New York Times, Estonia’s president tweeted that the country meets NATO’s defense-spending requirements and noted that the country had committed troops to the war in Afghanistan. “Estonia’s commitment to our NATO obligations is beyond doubt, and so should be the commitments by others,” an Estonian spokesperson told BuzzFeed News.