WARSAW, May 16 (Reuters) - United States Treasury Secretary Janet Yellen said on Monday that her talks with Polish officials had been good, but no breakthroughs in persuading them to back European Union plans to implement a global minimum corporate tax deal had been made.

"We've had very good discussions, good, frank discussions, in all of the meetings and we'll continue to work on all of the issues," Yellen told reporters during a visit to Warsaw. (Reporting by David Lawder, writing by Alan Charlish; Editing by Toby Chopra)