European mass migration crisis

Migrants walk to reach Pazarakule border gate, Edirne, Turkey, at the Turkish-Greek border on Sunday, March 1, 2020. Turkey's President Recep Tayyip Erdogan said his country's borders with Europe were open Saturday, making good on a longstanding threat to let refugees into the continent as thousands of migrants gathered at the frontier with Greece. (AP Photo/Emre Tazegul)

Leader of the Ordinary People and Independent Personalities party Igor Matovic addresses his supporters, acknowledging preliminary results of the general election in Trnava, Slovakia, Sunday, March 1, 2020. (AP Photo/Petr David Josek)

Greek border guards use teargas to push back migrants who try to enter Greece at the Pazarkule border gate, Edirne, Turkey, Saturday, Feb. 29, 2020. (Ismail Coskun/IHA via AP)

Migrants struggle to board a bus to go to the Greek border, in Istanbul, Friday, Feb. 28, 2020. NATO envoys were holding emergency talks Friday at the request of Turkey following the killing of 33 Turkish soldiers in northeast Syria, as scores of migrants gathered at Turkey's border with Greece seeking entry into Europe. (AP Photo/Omer Kuscu)

Migrants react as they walk to the border gate of Pazarkule in Edirne, near Turkey-Greece border, early Friday, Feb. 28, 2020. An air strike by Syrian government forces killed scores of Turkish soldiers in northeast Syria, a Turkish official said Friday, marking the largest death toll for Turkey in a single day since it first intervened in Syria in 2016. (AP Photo/Ergin Yildiz)

Migrants arrive with a dinghy accompanied by a Frontex vessel at the village of Skala Sikaminias, on the Greek island of Lesbos, after crossing the Aegean sea from Turkey, on Friday, Feb. 28, 2020. An air strike by Syrian government forces killed scores of Turkish soldiers in northeast Syria, a Turkish official said Friday, marking the largest death toll for Turkey in a single day since it first intervened in Syria in 2016. (AP Photo/Michael Varaklas)

Local residents gather at a roadblock in Karava, on the northeastern Aegean island of Lesbos, Greece, Thursday, Feb. 27, 2020. Greece's government hoped to defuse tensions after protests over plans for new migrant camps on two of its islands Wednesday turned into violent clashes between police and local residents, some armed with Molotov cocktails and shotguns.(AP Photo/Michael Varaklas)

Passengers ride on public transport in Caracas, Venezuela, Wednesday, Feb. 19, 2020. The debate over fresh U.S. sanctions aimed at forcing out Venezuela's Nicolás Maduro played out Wednesday across the crisis-stricken South American nation. Families have been split up with at least 4.5 million Venezuelans fleeing crumbling public services. (AP Photo/Ariana Cubillos)

FILE - In this Feb. 21, 2020, file photo, friends and relatives hold up photos of victims of a shooting, in Hanau, Germany. The rampage this week in Germany in which a gunman killed nine people with foreign backgrounds was the country's third deadly far-right attack in a matter of months. German leaders openly acknowledge there is a problem, but so far, identifying a solution has been elusive. (AP Photo/Martin Meissner, File)

Friends and relatives hold up photos of victims of a shooting, in Hanau, Germany, on Friday, Feb. 21, 2020. A 43-year-old German man shot dead nine people of immigrant backgrounds in the Frankfurt suburb of Hanau on Wednesday night before killing his mother and himself. He left a number of rambling texts and videos espousing racist views. (AP Photo/Martin Meissner)