On Tuesday, Sohn had met with President Lee Myung-bak and asked the president to renegotiate a deal on imports of U.S. beef. UDP spokeswoman Cha Young quoted Vershbow as telling Sohn in an unsolicited phone conversation on Wednesday morning he was "disappointed" that the party caused public "anxiety" about U.S. beef imports without presenting any scientific justification.

Sohn said it was inappropriate for the American ambassador to talk to an opposition party leader this way over the phone. He told Vershbow he should have come to see him in person or written a letter.

In making the conversation public, the UDP asked the U.S. Embassy to explain the envoy's phone call, which it said was out of tune with diplomatic protocol.

On Wednesday afternoon, Vershbow expressed a desire for private talks with Korean politicians, adding his telephone conversation with Sohn had been one such private conversation. He added it was “surprising” to see a political party make the content of such private talks public.

(englishnews@chosun.com )