Former Vice President Joseph R. Biden Jr., under pressure to respond to allegations that he touched and kissed a former Nevada assemblywoman, Lucy Flores, went on the defensive Sunday morning with a sweeping statement saying he did not believe he acted inappropriately but acknowledging that he had made “expressions of affection” during his years on the campaign trail.

In his statement, he emphasized that “not once — never — did I believe I acted inappropriately,” but pledged to listen to any accuser. He did not describe in detail the “expressions of affection,” but said there were also “countless handshakes, hugs” and attempts to “support and comfort” people he met.

“I may not recall these moments the same way, and I may be surprised at what I hear,” Mr. Biden said. “But we have arrived at an important time when women feel they can and should relate their experiences, and men should pay attention. And I will.”

[Who is Lucy Flores? A look at her career in politics and social justice activism.]

Mr. Biden, who is expected to announce in April whether he will join the 2020 Democratic primary field, issued his statement two days after an essay by Ms. Flores was published on Friday in New York Magazine’s The Cut. Ms. Flores, a Democrat, said she was 35 at the time of her encounter with Mr. Biden, who was then vice president.