Belarusian President Alexander Lukashenko has said it was "absolutely possible” his forces helped people cross into the European Union, but denied inviting them to the country.

European governments have accused Belarus of artificially creating the crisis by bringing in people from abroad and taking them to the border with promises of an easy crossing into the bloc. Belarus has denied the claim, instead criticising the EU for shutting its borders.

Asked if Belarus was helping refugees and migrants try and cross into Poland, Lukashenko said: "I think that’s absolutely possible.

"We’re Slavs. We have hearts. Our troops know the migrants are going to Germany … Maybe someone helped them,” he told the BBC. "But I didn’t invite them here,” he said.

Polish border guards on Friday said there were attempted crossings from Belarus by two groups of migrants and refugees on what is the eastern border of the European Union and NATO – one involving 500 people, some of whom threw rocks and tear gas canisters, aided by Belarusian authorities. The guards said they had arrested 45 people.

Al Jazeera, like all other media, is unable to independently verify claims about activity on the border as Poland has banned reporters from accessing the 3km (2 miles)-wide zone.

The accusation by Poland suggests the crisis has not been resolved by an apparent change of tack by Minsk, which on Thursday had cleared the main camps by the border and allowed the first repatriation flight to Iraq in months.

Aid groups say at least 11 asylum seekers and refugees have died on both sides of the border since the crisis began earlier this year – although the real number is believed to be higher – as concerns grow for people’s wellbeing amid freezing winter conditions.

Human rights groups say Poland has exacerbated the suffering by sending back those who try to cross. Poland says this is necessary to stop more people from coming.

Poland and its allies accuse Belarus of deliberately enticing thousands of migrants and refugees, many of whom are from the Middle East, and funnelling them to the country’s frontier with Poland in response to Western sanctions against Lukashenko’s government following his controversial re-election last year.

Minsk, backed by Russia, denies that and has accused Polish security forces of carrying out crimes against humanity while repelling people trying to enter the EU.

Lukashenko and his main ally, Russian President Vladimir Putin, spoke by phone on Friday and stressed "the importance of the establishment of cooperation between Minsk and the EU to resolve the problem”.

Meanwhile, Ukraine, which borders both Belarus and Poland, said it was preparing "systematically and thoroughly” in case the crisis shifted to its territory.

"We do not exclude the possibility that Russia will decide to purposefully send a large number of illegal migrants through Belarus to our territory,” Ukrainian Interior Minister Denys Monastyrsky told parliament.

He said the situation on Ukraine’s border was currently under control, but warned that migrants who decide to cross over will be pushed back with any means necessary, including firearms.

On Friday, Polish Defence Minister Mariusz Blaszczak tweeted that Warsaw was "happy to accept Estonia’s proposal” to send 100 troops to the border.

The migrants from the camps on the Belarusian side were taken on Thursday to a huge, crowded warehouse and journalists were permitted to film them. Children ran about on Friday morning, and men played cards while one dangled a toddler on his lap.

"This is not a life but this is not permanent, this should be just temporary until they decide our destiny: to take us to Europe or bring us back to our countries,” 23-year-old electrician Mohammed Noor told Reuters news agency.

"What I wish for myself, I wish it for others too – to go to Europe and live a stable life.”

Meanwhile in a hospital in Bielsk Podlaski, on the Polish side, two migrants who had been caught after crossing were given treatment before being taken away by Polish border guards.

Before he was taken away, Mansour Nassar, 42, a father of six from Aleppo, in Syria, who had travelled to Belarus from Lebanon, described his ordeal during five days in the forest.

"The Belarusian army told us: ‘If you come back, we will kill you’,” he said, in tears in his hospital bed. "We drank from ponds… Our people are always oppressed.”

Kassam Shahadah, a Syrian refugee doctor living in Poland who helps out in another hospital, said patients were terrified of being forcibly returned to Belarus.

"What they have seen, what they have lived through on that side is a nightmare for them,” he said.

The Council of Europe human rights commissioner Dunja Mijatovic called the humanitarian situation along the border "alarming” and demanded an end to Poland’s controversial returns of migrants to Belarus.

"I have personally listened to the appalling accounts of extreme suffering from desperate people … who spent weeks or even months in squalid and extreme conditions in the cold and wet woods due to these pushbacks,” she said in a statement.

"All pushbacks must end immediately.”

She also called on Poland to allow rights activists and media "immediate and unimpeded access to all areas along the border”.

Belarus said Thursday there were about 7,000 migrants in the ex-Soviet country.

Vladimir Sotnikov, a political scientist from the Russian Academy of Sciences, told Al Jazeera that a potential solution to this situation is for the EU to compromise.

"Probably, [a] solution could be.. [for the] EU [to] accept President Lukashenko as a legitimate president, and then Lukashenko could start negotiations with the EU just to defuse the crisis and to have a compromise,” he said.