Biden adviser rejects Republican call to ‘close skies’ over Ukraine

A senior Republican senator on Sunday urged the US and Nato to "close the skies" over Ukraine, hours after a logistics hub and training base for foreign fighters 11 miles from the Polish border was struck by Russian forces, killing 35.

"The message coming loud and clear is close the skies," said Rob Portman, a senator from Ohio on a visit to Poland. "Because the skies are where the bombs are coming, whether it's the missile attacks or the airplane attacks or with artillery."

The US intelligence community has assessed that any attempt to create a no-fly zone would risk escalation. The US has also turned down a Polish offer to supply jets to Ukraine via an American airbase in Germany.

Asked if supplying Ukraine with Russian-made MiG-29s could trigger a third world war, Portman told CNN's State of the Union he "didn't know why that would be true".

"The Russians have complained about everything," he said. "Vladimir Putin has said that the sanctions are an act of war."

Russia, Portman said, "complained when we provided Stingers directly from the US government, which can knock down an airplane and have been successful in doing that at lower altitudes. We have given [Ukraine] helicopters.

Portman welcomed an indication from Jake Sullivan, Biden's national security adviser, that anti-aircraft systems could be provided.

Sullivan repeated Joe Biden's opposition to the transfer of "offensive" weapons while underlining commitment to supplying "defensive" arms, telling CBS's Face the Nation the US and allies "believe in our capacity to continue to flow substantial amounts of military assistance, weapons and supplies to the front in Ukraine.

"We have been successful in doing so thus far and we believe we have a system in place that will allow us to continue to do so, notwithstanding Russian threats."

Russia claimed the strike on the Yavoriv base was against foreign fighters and weapons. The Pentagon spokesman, John Kirby, told ABC's This Week no Americans were at the facility.

But Kirby reiterated that the US and allies would "continue to flow and to move and to reposition forces and capabilities along Nato's eastern flank to make sure that we can defend every inch of Nato territory if we need to.

"We've made it very clear to Russia that Nato territory will be defended not just by the United States, but by our allies."

Of calls to supply jets or announce a no-fly zone, Kirby said: "We can all understand the kind of escalatory measure that might be perceived as."

The US deputy secretary of state, Wendy Sherman, said Russia showed signs of "willingness to have real, serious negotiations", despite four sets of talks having failed.

Sherman told Fox News Sunday the US had been working to "put enormous pressure on Vladimir Putin to try to change his calculus, to end this war, to get a ceasefire in the first instance, to get humanitarian corridors, and to end this invasion".

"That pressure is beginning to have some effect," Sherman said, though she added: "It appears that Vladimir Putin is intent on destroying Ukraine."

On Saturday, the White House approved an additional $200m of military assistance.

"We are determined and the Ukrainians are determined to ensure that anti-tank, anti-armor, anti-air capabilities, ammunition and other forms of assistance actually do make it to the front to blunt the Russian advance," Sullivan told NBC's Meet the Press. "We're coordinating the efforts of our allies and partners to do the same thing."

Last week, Biden warned of a "severe price" if Russia used chemical or biological weapons. Sullivan said Russian claims about supposed Ukrainian bio-weapons labs signaled that Moscow could be preparing to do so.

"When Russia starts accusing other countries of potentially doing something, it's a good tell that they may be on the cusp of doing it themselves," he said.

"What we're here to do is to deny them the capacity to have a false flag operation to blame this on the Ukrainians or on us, to take away their pretext and to make the world understand that if chemical weapons are used in Ukraine, it is the Russians who will have used them. And the response will, as the president said, be severe."

Sullivan will meet China's top diplomat, Yang Jiechi, in Rome next week. Sullivan said the US would respond to any attempts to work around western sanctions on Russia.

"We have made it clear to not just Beijing but every country in the world that if they think that they can basically bail Russia out, they can give Russia a workaround to the sanctions that we've imposed, they should have another thing coming because we will ensure that neither China, nor anyone else, can compensate Russia for these losses," Sullivan told NBC.

He declined to lay out what steps the US might take, saying: "We will communicate that privately to China, as we have already done and will continue to do."

Later, in response to reports Moscow had asked Beijing for military equipment, the Chinese embassy in the US said China's top priority was to prevent the situation in Ukraine from getting out of control.

The economic consequences of the war in Ukraine have yet to register heavily in US polls. On CNN, Portman deployed a Republican attack line, blaming Biden for not expanding domestic drilling for oil. Biden has countered that US oil companies have not exploited existing permits.

A CBS poll found that 77% of Americans across the political spectrum are willing to pay more for gas as a result of sanctions to punish Russia. According to the poll, 69% said economic pain now might be a wise hedge against bigger problems later.

Americans largely believe Russia has designs on invading other countries.