New Delhi, April 23 -- The European Union on Wednesday was on the cusp of approving a massive loan for Ukraine as oil began flowing again through a key pipeline toward Hungary and Slovakia, lifting a major obstacle to approving the funds.

The operator of the Druzhba pipeline in Ukraine, Ukrtransnaft, told the two countries that Russian oil was on its way and should arrive early on Thursday. Unlike most of the rest of the EU, Hungary and Slovakia still depend on Russia for their energy needs.

EU envoys, meanwhile, launched a political procedure to endorse the loan. National governments have 24 hours to raise objections in writing, and if none of the 27 member nations do, the loan could be approved by Thursday afternoon, just as EU leader...