German Chancellor Friedrich Merz on Sunday told DW that Europe was facing a "deep threat" to its security architecture as negotiations continue in Geneva over a controversial US plan.

Merz said Ukraine's sovereignty must not be sacrificed as part of any arrangement, which Washington wants agreed by Thursday.

What did Merz say about the Ukraine plan?

Speaking to DW's Michaela Küfner after the G20 summit in Johannesburg, Merz said Europe had known about the proposal and confirmed he had spoken with US President Donald Trump before traveling to South Africa.

"We are aware of this 28-point plan since last Friday," Merz said. "I had a call with President Trump before I left the country. I told him that we could agree on some of them, but there are others we could not agree, and I told him that we are fully in line with Ukraine, that the sovereignty of this country must not be jeopardized."

He said negotiations in Geneva were serious and were being led by national security advisers from the US, Ukraine and Europe. "We do not know what the outcome of these talks could be," Merz said. "At the very end of the day, the sovereignty of Ukraine may not be questioned."

Ukraine's European allies have pushed back on the plan, which required Kyiv to give up large areas of territory to Russia and limit the size of its military, as well as other measures.

Merz said the war had destabilized Europe for almost four years. "We are seeing severe attacks on our infrastructure. We are seeing severe attacks on our cybersecurity. So this is a deep threat for the entire political order of the European continent," he said. "That's the reason why we are so engaged."

He also warned that Trump's Thursday deadline for agreement on all the details is unrealistic. "I think that it's not achievable to have all the 28 points agreed," he said, referring to the extent of what could be achieved over the specific timescale.

What did Merz say about Europe's role?

Merz confirmed Europe was instead proposing a "smaller step" and that it held some influence on what was possible.

"We are trying to figure out which part of this plan could be achieved unanimously between the Europeans, the Americans and Ukraine on the one side, and the Russians on the other side," he said. "This is extremely complicated… we are now trying to implement an intermediate step until Thursday. And I know that President Trump is really interested in having at least an intermediary result by Thursday."

Merz stressed that Europe holds leverage over key elements of the plan. "The Russian assets, which are based in Brussels, cannot be paid out to the Americans. That is unthinkable," he said. "So if this plan comes into reality, the support of the Europeans is definitely needed."

Merz also said Beijing could also help pressure Moscow. "China could play a role. China could put some more pressure on Russia to end this war," he said.

The chancellor added that he had held a "very long meeting" with Chinese Premier Li Qiang while preparing a state visit next year. He said he hoped a ceasefire could be reached before that visit takes place.

Edited by: Karl Sexton