No more normal course of business than it would have been to send condolences on the death of Himmler, or Arafat, or Castro—unless, of course, you happen to be on their side instead of the side of your own country, in which case you should be something other than Secretary of State.
I may have misspoke….
Death and state funeral of Leonid Brezhnev
https://en.wikipedia.org/wiki/Death_and_state_funeral_of_Leonid_Brezhnev
Speaking at a Veterans Day ceremony, American President Ronald Reagan called Brezhnev “one of the world’s most important figures for nearly two decades” while expressing his hope for an improvement in Soviet–US relations.[76] Reagan then visited the Soviet embassy in Washington, D.C., on 13 November to sign a message in the embassy’s condolence book.[77] Reagan later described having “a strange feeling in that place”, noting how no one, except the ambassador, was smiling.[78] Ambassador Anatoly Dobrynin noticed Reagan appearing “guarded and very inhibited when entering the embassy ... wondering what kind of place it was”, but stated that Reagan seemed “more in his element by the end of his visit”.[79]