Nato's new chief, Mark Rutte, on Tuesday sought to allay concerns about the potential impact of a Donald Trump victory in the upcoming US elections, vowing to continue supporting Ukraine as he took over the leadership of the world's most powerful military alliance.

The former Dutch prime minister assumes the role at a critical juncture, with Russia intensifying its war in Ukraine and China demonstrating its growing influence, just weeks before American voters head to the polls.

"I am committed to preparing Nato for the challenges of the future," Rutte stated as he formally succeeded Norway's Jen Stoltenberg at Nato's Brussels headquarters. The outcome of the November 5 vote will be Rutte's first major test and will shape his initial four-year term.

During his campaign, former US President Trump has threatened to withhold protection from Nato members who do not sufficiently invest in defense and has promised to swiftly negotiate a deal with Russian President Vladimir Putin to end the war in Ukraine.

"I am not concerned. I know both candidates well. I worked with Donald Trump for four years. He was the one pushing us to spend more, and he succeeded," Rutte said. "I will be able to work with either, regardless of the election's outcome."

By choosing the seasoned Dutch statesman, a steadfast US ally and strong supporter of Ukraine, Nato's 32 nations have selected a leader who will continue to advocate for Kyiv and strengthen the alliance's defenses against Russia.

"Nato will be in safe hands with you at the helm," Stoltenberg said, reflecting on his guidance through one of the alliance's most turbulent decades.

Rutte listed supporting Kyiv as one of his top priorities, along with ensuring Nato continues to invest more in defense and enhancing ties with partners, including the European Union and those in the Asia Pacific.

"Putin must understand that we will not yield, and we want Ukraine to prevail in the end," Rutte warned, emphasizing his desire to increase support for Ukraine and bring it closer to Nato.

"We must sustain this support into the future, because Ukraine's rightful place is in Nato," he added.

Ukraine's President Volodymyr Zelensky expressed his commitment to working productively with Rutte as his country continues its journey toward full-fledged Nato membership.

However, Kyiv faces a challenging moment as Russian forces advance on the battlefield more than three-and-a-half years after the Kremlin's full-scale invasion. Uncertainty surrounds future Western support for Ukraine, and there are growing calls for a resolution to the conflict.

"It is up to the Ukrainian government to decide when they are ready to discuss peace," Rutte said. "That is for later."

Rutte supported Ukraine's right to use Western-supplied weapons within Russia but noted that any limitations would be decided by each Nato ally.