Finland and Norway sought to ease migrant flows from Russia, as tensions over Europe's refugee crisis spread to the continent's northernmost frontiers.
Finland criticized its eastern neighbor Wednesday for allowing increasing numbers of asylum seekers across their Arctic border.
"I have understood that no one moves forward in the Russian border zone without Russian authorities being aware of it. I'm disappointed," Interior Minister Petteri Orpo told Finnish news agency STT.
He said he wanted to discuss the situation with Moscow, adding that the sudden rise could not be explained by a recent crackdown on asylum seekers by Norway's right-wing government.
Despite the onset of winter, migrants escaping war and poverty in the Middle East and Africa have continued to pour into Europe in large numbers, leading several countries to step up efforts to restrict flows.
Austria said Wednesday that it would cap the number of people allowed to claim asylum this year at less than half last year's total, and its chancellor said border controls would be tightened significantly.
Further north, up to 20 asylum seekers a day are reaching Finland from Russia at the Salla checkpoint, according to the Finnish border guard. Last year, just 700 made the same crossing.
Finland has banned crossings there on foot or bicycle, so asylum seekers have begun using old Russian cars, about 50 of which lie frozen there after being confiscated.
Meanwhile, Norway sent a first bus carrying 13 migrants from Syria, Afghanistan, Yemen and Pakistan back across its Arctic border with Russia on Tuesday night in temperatures of around -30 degrees Celsius (-22 Fahrenheit).
Sylvi Listhaug, Minister of Immigration and Integration, told parliament the government was returning only those who had long-term visas to stay in Russia.
But last week, the U.N. refugee agency warned Norway that Russia offered inadequate protection, and other critics say Norway did not give the asylum seekers the right to challenge the decision.