The new US ambassador to the United Nations on Thursday strongly condemned Russia's "aggressive actions" in Ukraine, amid concerns that President Donald Trump was considering relaxing American sanctions against Moscow. "This escalation of violence must stop," Nikki Haley said in her first public remarks to the UN Security Council at a meeting held to address the recent upsurge of violence in the conflict. "The United States stands with the people of Ukraine, who have suffered for nearly three years under Russian occupation and military intervention," Haley said. The US would like to have better relations with Russia, but that does not mean the US should not condemn the "dire situation in eastern Ukraine," she added. Haley said she found it "unfortunate" that she had to make the comments. Ukrainian President Petro Poroshenko said in an interview Wednesday that a relaxation of international sanctions would "shore up Russian aggression against Ukraine and bring all of Europe into danger." Several people were killed in recent days amid a surge of violence that erupted ahead of Ukraine assuming the month-long presidency of the United Nations Security Council on Wednesday. Russian-backed separatists and the Ukrainian military have been fighting for control of Ukraine's two eastern-most regions for three years. The conflict erupted in early 2014 as Ukraine ousted its pro-Russian president amid mass protests calling for closer ties with the European Union. About 10,000 people have been killed in the conflict, according to UN estimates.