Ukrainian President Volodymyr Zelensky arrived in Oslo on Tuesday for talks with top US envoys in a bid to get strained relations with Washington "on a more constructive path", Oslo said.
"We are maintaining all contacts that can help bring peace," Zelensky said in a social media post announcing his arrival in Oslo.
Norway's Prime Minister Jonas Gahr Store said earlier that Oslo would host talks between Zelensky, US envoys Steve Witkoff and Jared Kushner -- the latter taking part remotely -- as well as Finnish President Alexander Stubb.
Relations between Kyiv and Washington have soured since President Donald Trump partially lifted sanctions to strike a diesel-supply deal with Russia's Vladimir Putin and slammed Zelensky as a warmonger for Ukrainian attacks on Russian oil refineries.
Zelensky has accused the United States of deliberately withholding vital intelligence and delaying military aid, saying on Monday that Ukraine received no early warning of powerful Russian missile strikes that targeted energy facilities in the capital region.
US-led diplomatic efforts to end Europe's deadliest conflict since World War II have stalled in recent months, as Washington has shifted focus towards the war with Iran.
The Norway talks were due to begin on Tuesday afternoon and continue into the evening, Store told reporters.
"The aim is to put diplomatic efforts on a more constructive path," he said.
Ahead of the meeting, Zelensky on Tuesday said he held "substantive" and "constructive" talks with US Secretary of State Marco Rubio, in which he insisted that the US military satellite system Ukraine uses, Starshield, "needs to be restored" and that ballistic missile interceptors "are needed to protect lives".
Zelensky told US senators on Monday that "the Pentagon is delaying the delivery of missiles" already paid for by European countries, and that the shipment was waiting for US Defence Secretary Pete Hegseth's signature.
He said several European countries were ready to transfer Patriot interceptor missiles from their own stockpiles but were still awaiting US approval.
The United States has denied making any changes to intelligence sharing with Ukraine, and Rubio on Tuesday said Washington was not deliberately withholding supplies.
"There's nothing being deliberately denied to Ukraine," Rubio said while on a trip to India.
"It's simply, it's a balance between our obligations to other partners and frankly our own... requirements for our own facilities as well."
Trump has also denied ordering a reduction in speeds on the US government-owned and -controlled Starshield network after Elon Musk, whose company SpaceX developed it, said the order could only have come from the White House.
The US leader has accused his counterpart of not trying to resolve the conflict with Russia.
"Zelensky doesn't know what he's talking about," Trump said on Monday.
"To be honest, I think it's time for somebody else to negotiate on behalf of Ukraine."
Trump said he was ready to meet Putin and Chinese leader Xi Jinping in China next month to discuss denuclearisation, adding that talks could also cover the Ukraine war -- fuelling fears in Kyiv that it was being sidelined.
Kremlin spokesman Dmitry Peskov confirmed earlier that "the topic of such a hypothetical has indeed been mentioned" when asked about a Wall Street Journal report on Sunday that Trump, Putin and Xi could meet.
Ukraine's Foreign Minister Andriy Sybiga said that such a meeting would "only encourage Putin to continue this war".
News outlet Axios reported that Witkoff would travel from Oslo to Russia to meet Putin.
"We hope that it will be possible to arrange a meeting in the very near future, allowing the American negotiators... Mr Witkoff, to brief President Putin on their contacts with both the Ukrainians and the Europeans," Peskov told reporters Tuesday.
Ukrainian authorities said Tuesday that Russian strikes killed at least six people around the country, as Moscow targets energy and transport infrastructure with winter approaching.
The attacks came after Zelensky said Kyiv would resume hitting Russian refineries in the face of unrelenting strikes, more than four-and-a-half years into the war.