In Ukraine, the focus is the fighting, but are negotiations possible?

A wounded Ukrainian soldier who goes by the call sign Flame awaits evacuation after being injured in fighting near the eastern town of Bakhmut, Ukraine, on Sept. 4. Ukraine has been waging an offensive against Russian forces since June, but so far has made only limited gains. Libkos/AP hide caption

toggle caption Libkos/AP

A wounded Ukrainian soldier who goes by the call sign Flame awaits evacuation after being injured in fighting near the eastern town of Bakhmut, Ukraine, on Sept. 4. Ukraine has been waging an offensive against Russian forces since June, but so far has made only limited gains.

Libkos/AP

When Volodymyr Zelenskyy is asked if Ukraine should negotiate with Russian leader Vladimir Putin, the Ukrainian president is blunt.

"When you want to have compromises or have dialogue with somebody, you can't do it with a liar," Zelenskyy recently told CNN.

Zelenskyy and many Ukrainians are quick to note that Moscow has dominated, or attempted to dominate, Ukraine for generations. They say Ukraine's goal is clear: drive out all Russian troops, estimated at 200,000 or more, even if that means a protracted war.

Yet Ukraine's military offensive, which began back in June, is making only limited progress against the Russian forces that still hold about 16 percent of Ukraine's territory in the south and the east. The frontlines on the battlefield today have changed only marginally this year despite months of fierce fighting.

"When this offensive reaches its limits, which it will probably do in a couple of months, when it gets muddy, what do we do then?" said , a former diplomat and national security official who now teaches at Georgetown University.

He was part of a small, unofficial group that met quietly this year with Russian officials, including Foreign Minister Sergey Lavrov.

He's been arguing that the U.S. approach should be bolster Ukraine's military, as it's doing, and also prepare for possible negotiations.

"Ukraine is suffering a terrible loss of life," said Kupchan. "As a consequence, one has to ask, 'Might Ukraine be better off trying to get a cease-fire and beginning the process of rebuilding?'"

Kupchan has faced considerable pushback in the U.S. and Ukraine for raising the possibility of cease-fire or a permanent agreement. According to polls in Ukraine, a large majority are prepared to keep on fighting with the aim of ousting all the Russians, despite the growing number of casualties, economic hardship and destruction throughout the country.

Ukrainian troops pay respects at the coffin of Ukrainian serviceman Sergiy Yarmolenko in Kyiv on Thursday. Yarmolenko was killed in recent fighting with Russian forces. Efrem Lukatsky/AP hide caption

toggle caption Efrem Lukatsky/AP

Ukrainian troops pay respects at the coffin of Ukrainian serviceman Sergiy Yarmolenko in Kyiv on Thursday. Yarmolenko was killed in recent fighting with Russian forces.

Efrem Lukatsky/AP

Spotlight remains on Ukraine's offensive

As a result, the focus remains very much on Ukraine's offensive in the south and east. The Ukrainians have made some gains over the summer, advancing a few miles here and there and reclaiming a number of villages.

, a former general who commanded the U.S. Army in Europe, believes Ukraine could make significant advances in the coming weeks, before the fighting is expected to slow over the late fall and the winter.

The Ukrainians are inflicting damage on Russia forces behind the front lines, he noted, something that gets only limited attention.

"Every time a Russian train is stopped or a truck is destroyed or a bridge is taken out, that makes it that much harder to resupply Russian troops and Russian artillery," said Hodges, who now lives in Germany. "The Ukrainian counteroffensive is putting enormous pressure on the Russians."

He favors additional weapons for Ukraine, including the ATACM, a U.S. missile with a range of nearly 200 miles. This would allow Ukraine to carry out even more long-range attacks, further straining Russian supply lines.

The Biden administration, which is considering adding ATACMS to Ukraine's arsenal, has provided or pledged more than $100 billion in overall assistance to Ukraine since early last year, and is now seeking another $24 billion. Military aid makes up most of those figures, but they also include funding for the government and humanitarian aid.

For now, bipartisan support for Ukraine holds

Most members of Congress, Republicans and Democrats, have so far supported such aid. But opposition is growing. Former president Donald Trump, as well as other Republican presidential candidates, are among the critics.

Hodges said that in order maintain the current levels of support in the U.S., the Biden administration should define more clearly what success in Ukraine would look like.

Would it be an outright Ukrainian military victory, or something lesser, like a negotiated settlement that might leave Russia in control of some parts of Ukraine?

When pressed, President Biden and his administration say it will support Ukraine for "as long as it takes."

Hodges finds that wording too fuzzy.

"We run the risk of losing some of what is so far very strong, effective bipartisan support," he said. "That's exactly what the Kremlin is hoping for, is that the support will eventually fall away."

, a former Pentagon official, supports U.S. help for Ukraine, though he thinks European nations should be in the lead.

His main concern is that a long-running war in Ukraine diverts U.S. attention from China and a possible invasion of Taiwan — which he considers much more important.

"There's always a tradeoff. You may not acknowledge it or know where exactly where it is, but it's going to come," said Colby. "My argument has been that Europe has really got to take a leading role there because of the urgency of the threat in the Pacific."

As a group, European nations are providing to Ukraine, similar to the U.S., though politically the U.S. has set the tone for the Western response.

Meanwhile, neither Russia nor Ukraine is expressing interest in negotiations. Russia annexed four Ukrainian regions and claims them as permanent Russian territory. Ukraine says it will not give up any land.

Charles Kupchan acknowledges it will be hard enough to launch talks, and harder still to reach agreement. But he said it's important to be ready if and when an opportunity arises.

"It requires preparation and it needs to be on the shelf if, in fact, both Kyiv and Moscow arrive at the conclusion that it's worth talking" he said.

For now, the focus is still on the fighting.