SILVER SPRING, Md. — One labor leader who heard Hillary Clinton’s private pitch Thursday for the AFL-CIO presidential endorsement came away unimpressed by her “cautious” message and her refusal to take a position on the Pacific trade pact, which organized labor fiercely opposes.

RoseAnn DeMoro, executive director of National Nurses United and a member of the labor federation’s executive council, said in an interview that Mrs. Clinton was “non-committal” on the Trans-Pacific Partnership, a “bedrock issue” for the labor movement. Many union leaders predict that, if enacted, the TPP will result in jobs moving overseas and new strains for U.S. workers.