Washington, Mar 21 (IANS): Linda Thomas-Greenfield, the US Ambassador to the UN, has warned that there was little immediate hope of a negotiated end to the war in Ukraine, as pressure continued to build on American President Joe Biden ahead of a crucial NATO summit in Europe this week, the Guardian reported.

Biden, who faces growing dissatisfaction over his approach to the war, will travel to Brussels on Thursday and then on to Poland, it was announced on Sunday night.

He will hear a proposal from Poland for NATO to send a peacekeeping force into Ukraine, something Thomas-Greenfield said was unlikely, according to the Guardian reported.

The Ambassador said she saw little chance of a breakthrough.

"We have supported the negotiations that (Ukrainian) President Zelensky has attempted with the Russians, and I use the word attempted because the negotiations seem to be one-sided, and the Russians have not leaned in to any possibility for a negotiated and diplomatic solution," she said.

"We tried before Russia decided to move forward in this brutal attack on Ukraine and those diplomatic efforts were not responded to well by the Russians, and they're not responding now. But we're still hopeful that the Ukrainian effort will end this brutal war."

Thomas-Greenfield talked down the prospects of a NATO peacekeeping force in Ukraine.

"I can't preview what decisions will be made and how Nato will respond to the Polish proposal... What I can say is American troops will not be on the ground in Ukraine at this moment. The President has been clear on that.

"Other NATO countries may decide that they want to put troops inside of Ukraine, that will be a decision that they have made. We don't want to escalate this into a war with the US but we will support our NATO allies," the envoy added.