Germany's Gabriel says communication channel with Turkey must remain open

ATHENS (Reuters) - Communication channels between the European Union and Turkey must remain open, Germany's foreign minister said on Thursday in an escalating row over campaigning by Turkish politicians in Europe. Turkey has been embroiled in a dispute with Germany and the Netherlands over campaign appearances by Turkish officials seeking to drum up support for an April 16 referendum that could boost Turkish President Tayyip Erdogan's powers. "Turkey certainly isn't on the verge of joining (the EU), but in no case should we close communication channels, even though things are difficult," Foreign Minister Sigmar Gabriel told reporters during an official visit to Athens. Ankara has accused its European allies of using "Nazi methods" by banning Turkish ministers from addressing rallies in Europe over security concerns. The comments have led to a sharp deterioration in ties with the European Union, which Turkey still aspires to join. (Reporting By Renee Maltezou, writing by Michele Kambas)