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Migrants are escorted through fields by police as they are walked from the village of Rigonce to Brezice refugee camp on Oct. 23, 2015 in Rigonce, Slovenia. Jeff J Mitchell/Getty Images

More than 1 million refugees and migrants have arrived by land and sea in the European Union this year in the fallout of war, poverty and persecution in Africa and the Middle East, the U.N. refugee agency and the International Organization for Migration (IOM) said Tuesday. The number of people displaced by war and conflict is the highest seen in Western and Central Europe since the 1990s, the two agencies said in a joint statement.

Half of those arriving this year were Syrians escaping the war-torn country, while another 20 percent were Afghans, and 7 percent were Iraqis, the agencies said in the report. Nearly 3,700 others died trying to cross the Mediterranean on rickety boats.

Around 972,500 people had crossed the Mediterranean Sea by Dec. 21, according to the U.N. refugee agency. In addition, IOM estimates that over 34,000 have crossed from Turkey into Bulgaria and Greece by land.

"We know migration is inevitable, it’s necessary and it’s desirable," IOM chief William Lacy Swing said in the statement. "But it’s not enough to count the number of those arriving — or the nearly 4,000 this year reported missing or drowned. We must also act. Migration must be legal, safe and secure for all — both for the migrants themselves and the countries that will become their new home."

Of the total of a million arrivals, a vast majority -- over 800,000 refugees -- arrived by Aegean Sea from Turkey to Greece by Dec. 21, according to IOM.

European nations are struggling with a massive influx of refugees fleeing war and poverty in Middle Eastern and African nations. The crisis has not only triggered the rise of anti-EU and anti-immigrant parties across Europe, but has also endangered the bloc’s much-cherished Schengen free-movement zone, as countries begin to impose strict border controls.

The U.N. refugee agency, the United Nations High Commissioner for Refugees, is reportedly planning for arrivals to continue at a similar rate in 2016, but IOM spokesman Joel Millman said it was impossible to forecast future numbers.

"So much is in the balance, the resolution of the Syrian war, and the disposition of the European border protection moves that are being contemplated," Millman reportedly said. "We never thought it would reach this level. We just hope people are treated with dignity."