Adds details on USTR Greer's concerns and plans for public comments from second paragraph

May 29 (Reuters) - The Trump administration on Friday opened an unfair trade practices investigation into Vietnam's intellectual property protection policies and enforcement that may lead to new tariffs or other trade measures, the U.S. Trade Representative's office said.

Vietnam was identified as a priority country by the USTR on April 30 "due to its persistent failure to resolve long-standing concerns about IP protection and enforcement."

During U.S. President Donald Trump's first administration, USTR used a Section 301 investigation into China's intellectual property misappropriation and technology transfer practices to impose sweeping tariffs of 25% on hundreds of billions of dollars' worth of annual Chinese imports.

U.S. Trade Representative Jamieson Greer said in a statement that while Vietnam has taken some steps in recent years to address intellectual property concerns, infringement "continues to impair the competitive position of U.S. innovators and creators."

"We need to see Vietnam resolve these long-standing concerns, including on a range of IP enforcement issues, in a manner that is sustained and that deters future IP infringements," Greer said.

USTR said in a Federal Register notice that it has opened a docket for public comments on the matter through July 2.