Hungary will block a 90-billion-euro ($106 billion) EU loan for Ukraine until it resumes oil shipments to the country via the Druzhba pipeline, its foreign minister said on Friday after Budapest said it would tap strategic reserves to tackle a shortage. Hungary and Slovakia, which have the only remaining refineries in the European Union using Russian oil through Druzhba, have been trying to secure supply since flows were halted on January 27 following what Ukraine said was a Russian drone attack that damaged pipeline infrastructure. Both countries have blamed Ukraine for the delay in restarting the flows for political reasons.