The resignation of Rob Portman as U.S. trade representative will probably impede the progress of trade liberalization talks taking place under the World Trade Organization, Mamoru Ishihara, Japan's vice minister of agriculture, forestry and fisheries, said Thursday.
"The prospects for the WTO negotiations have become even murkier with Mr. Portman stepping down," Ishihara said.
Portman is leaving his post as top U.S. trade negotiator at a time when WTO members are struggling to meet the April 30 deadline to determine guidelines aimed at reducing trade barriers in both farm and nonfarm products.
Ministerial conferences comprising six important WTO members -- the U.S., EU, Brazil, India and Australia -- are leading the talks at the so-called Doha round.
Aside from Portman's departure, stark differences among WTO member states that seem bent on protecting the interests of domestic producers will likely doom the goal of concluding a deal by the end of this month, many political observers say.
U.S. President George W. Bush on Tuesday named Portman budget director at the White House.