Newly confirmed U.S. Ambassador to the United Nations Mike Waltz took his seat at the U.N. Security Council for the first time Monday, using the occasion to reaffirm Washington's commitment to NATO amid reports of Russian airspace violations in Estonia.

In brief remarks delivered calmly from the council's iconic horseshoe table, Waltz underscored U.S. solidarity with its allies.

"The United States stands by our NATO allies in the face of these airspace violations," Waltz said, according to reports on X. "And I want to take this first opportunity to repeat and to emphasize the United States and our allies will defend every inch of NATO territory."

Waltz's confirmation by the Senate ended weeks of delay, and his debut comes as tensions with Moscow intensify over military incursions along NATO's eastern flank.

The Senate confirmed Waltz on Friday, filling the last vacancy in President Donald Trump's Cabinet after eight months of delays and the withdrawal of a previous nominee.

The bipartisan vote for Waltz came after a recent procedural hurdle sent his nomination back to the Senate Foreign Relations Committee, where it had to be voted on again Wednesday.

"I congratulate Mike Waltz on his appointment as US Ambassador to the UN," Israeli Ambassador to the U.N. Danny Danon lauded in a statement. "Mike is a warrior, statesman and true friend of Israel.

"His appointment is vital news in cementing the alliance between Israel and the US. In the face of the delegitimization campaigns and hypocritical discourse at the UN, we will stand together shoulder to shoulder, in pursuit of justice and security. We are looking forward to you joining us here at the UN, Mike."