"I'm doing it because I hope we can negotiate an end to this for the good of the country and because I have high regard for the president and for Bob Mueller," Giuliani told The Washington Post.
Trump told reporters Wednesday that Rosenstein and Mueller are "still here" despite rumors about the president firing them.
Trump aims to give a boost to Blackburn in a red-state race Republicans cannot afford to lose in November.
Nearly 60 House members will not run for re-election this year, with most departures coming on the Republican side.
Mueller is leading the investigation into whether the Trump campaign coordinated with Russia, and Rosenstein appointed him.
Trump and Abe will likely address efforts to deter North Korea's nuclear and missile programs
The Quinnipiac poll of Texas suggests Ted Cruz will have to work to retain the Senate seat against Beto O'Rourke.
"I'm not going to campaign against someone who I've been a friend with and worked with," Sen. Bob Corker says of Democrat Phil Bredesen.
With just under seven months remaining until the midterms, Democrats have a solid lead on the generic congressional ballot in Pennsylvania.
Rep. Charlie Dent, R-Pa., announces he will leave Congress in the "coming weeks."