Switzerland has temporarily suspended participation in a UN programme aimed at resettling vulnerable refugees, blaming incapacity as it faces an influx of people fleeing Ukraine, authorities confirmed Monday.

The Swiss State Secretariat for Migration (SEM) confirmed reports that the wealthy Alpine nation had suspended admissions of refugees under the United Nations refugee agency's resettlement programme.

"The resettlement programme will not be called into question, only admissions will be temporarily suspended," SEM spokesman Lukas Rieder told AFP in an email.

The UNHCR has been working to resettle to third countries some of the world's most vulnerable refugees living in precarious conditions.

For 2022, UNHCR had estimated that nearly 1.5 million refugees were in need of resettlement, although only a fraction of those spots were made available.

Switzerland, with a population of 8.7 million, had committed to resettling 1,820 vulnerable refugees in 2022 and 2023.

But the Le Temps and NZZ am Sontag papers reported that the justice ministry decided in late November to suspend the programme.

Rieder attributed the decision to "severe pressure" on Switzerland's asylum system, especially in terms of accommodation capacity and staff.

Around 100,000 asylum seekers and refugees, including more than 70,000 fleeing the war in Ukraine, have arrived in Switzerland since the start of the year, reportedly the largest such number since World War II.

"Therefore, the task force in charge recommended the temporary suspension of admissions under the 2022/2023 resettlement programme," Rieder said.

By mid-December, 641 people had already been resettled under the programme, and he said that around 400 refugees who have already received a positive admission decision will be admitted by next March.

But the remainder would need to wait.

That decision would be re-evaluated during the first half of 2023, Rieder said.

According to Le Temps, the refugees in question are mostly from Afghanistan, Sudan and Syria, and mainly comprise of women, children and people with health conditions who are deemed particularly vulnerable by UNHCR.