ATHENS—Greece “can do more” to investigate reports it has pushed asylum-seekers back to Turkey, a senior European Union official said on March 29, as Greek authorities pledged that a new migrant reception center on the island of Lesbos would open in time for winter. The United Nations refugee agency (UNHCR) has said it has received a growing number of reports in recent months suggesting asylum-seekers may have been pushed back to Turkey at sea or immediately after reaching Greek soil or left adrift at sea. Greek officials have always rejected the reports. “I am very concerned about the UNHCR report and there are some specific cases that I really think need to be looked into closer,” Ylva Johansson, the EU’s home affairs commissioner, said during a visit to the island of Lesbos. “I think the Greek authorities can do more when it comes to investigating these alleged pushbacks.” Greece’s Migration …