Spectre of reprisals over EU arms shipments to Ukraine

Poland has several Russian-made Mig fighter jets that could be made available to Ukrainian pilots, but Stoltenberg's host indicated his country wouldn't be sending combat aircraft

"We are not sending any jets to Ukraine because that would open a military interference in the Ukrainian conflict," Polish president Andrzej Duda said alongside the Nato chief.

"We are not sending any jets to the Ukrainian airspace," Duda said.

As for any other Polish weapons headed for the front line, a Polish diplomatic source said: "We won't give any precise details, because the person [Russian president Vladimir Putin] on the other side is entirely unpredictable."

Slovak and Bulgarian diplomats, speaking to EUobserver, denied earlier Ukrainian reports that their countries were offering up old Mig fighter planes to Ukraine.

EU foreign affairs chief Josep Borrell late on Sunday had said "we are going to provide even fighter jets" in an EU arms-to-Ukraine programme, which includes €450m of EU subsidies, prompting a round of speculation about where the aircraft would come from.

Ukraine has also appealed for Nato to impose a no-fly zone over Ukraine.

But that idea was rejected out of hand by British prime minister Boris Johnson, who, like Stoltenberg, was visiting Poland and Estonia on Tuesday.

A no-fly zone would mean "shooting down Russian planes — that's a very big step and that is simply not on the agenda of any Nato country," Johnson told a press conference at an Estonian military base in Tapa, speaking alongside Stoltenberg and Estonian prime minister Kaja Kallas.

Asked if the UK is helping British volunteers to get into Ukraine to fight Russia, Johnson also said his country was "doing no such thing."

There are trip-wire sensitivities in the standoff between Western allies and Russia over Ukraine.

"We're waging an all-out economic and financial war on Russia," French finance minister Bruno Le Maire told France Info radio on Tuesday, referring to EU economic sanctions on Russia.

"Watch your tongue, gentlemen! And don't forget that in human history, economic wars quite often turned into real ones," Russian former president Dmitry Medvedev tweeted back from Moscow.

Le Maire, speaking afterward to the AFP news agency, said he had misspoken in using the term "war."

"We are not in a battle against the Russian people," he said.

Jets aside, several Nato and EU states, such as Denmark and Sweden, have also pledged to send thousands of anti-tank and anti-aircraft rockets, to be picked up by Ukrainian soldiers on their western borders.

"I'm not going to tell you anything," on how the deliveries were being made, a Swedish defence spokesman told EUobserver, citing security concerns.

"The last shipment of Danish anti-tank weapons to Ukraine was delivered on Tuesday afternoon. And the Danish Hercules plane has returned home safely tonight. Thank you so much for a huge effort. You make Denmark proud!" Danish defence minister Morten Bødskov tweeted Tuesday evening.

But technical glitches also risk holding back supplies: 300 spare Danish 'Stinger' anti-aircraft missiles due to go to Ukraine first had to be shipped to the US to be outfitted with new parts, Danish media reported.

Johnson said Russian missile strikes on Kharkiv, Ukraine's second largest city, on Tuesday morning, reminded him of Serbian war crimes in Bosnia.

"It's absolutely sickening. It reminds me, if anything, of the shelling of Sarajevo market [in Bosnia in 1994]," Johnson said, speaking in Tapa.

Nato did ultimately intervene in the Western Balkans, but still failed to stop acts of genocide, such as at Srebrenica in 1995.

Putin was "evil" and Russia had "gone from being a difficult neighbour to a rogue state," Estonia's Kallas said Tuesday.

"Lukashenko's troops have also entered Ukraine," said Kallas, referring to Belarusian president Alexander Lukashenko, Putin's ally, in what amounted to the first major sign the Ukraine war is drawing in neighbouring states.