US Ambassador Nikki Haley

US Ambassador Nikki Haley on Tuesday said the United States is ready to improve ties with Russia but will not compromise on its support for NATO and the European Union.

Haley told a Security Council debate on conflicts in Europe that “Russia’s attempts to destabilize Ukraine” were among the most serious challenges facing the continent.

“The United States thinks it’s possible to have a better relationship with Russia — after all, we confront many of the same threats,” Haley said.

“But greater cooperation with Russia cannot come at the expense of the security of our European friends and allies.”

The remarks came as European governments are seeking reassurance after US President Donald Trump applauded Britain’s decision to leave the European Union, criticized NATO members over burden-sharing and praised Russian President Vladimir Putin.

Haley said the United States was committed to “the institutions that keep Europe safe” and that it “will not waver” in its support for the North Atlantic Treaty Organization.

The United States wants to deepen cooperation within NATO while “keeping the door open to new allies,” she said.

Enlarging NATO has been a major bone of contention with Russia, which sees any expansion of the military alliance in eastern Europe as a policy of containment directed against Moscow.

Haley described US ties with the European Union as “deep and enduring” and said differences with European governments should not be seen as a shift in US support.

“No one should misinterpret occasional policy differences and debates as a signal of anything less than total commitment to our alliances in Europe. That commitment is strong,” she said.

The ambassador stressed that the US and the EU were united in the view that sanctions against Russia would remain in place until Russia returns Crimea to Ukrainian rule.

A recent flareup of fighting in east Ukraine “show the consequences of Russia’s ongoing interference in Ukraine,” said the US ambassador.

Haley said Russia’s decision to recognize passports issued by separatist in Ukraine’s Lugansk and Donetsk regions was “another direct challenge in the efforts to bring peace to eastern Ukraine.”