On 9th of June, Donald Trump and his Romanian counterpart (Klaus Iohannis) held a press conference.
That was a very important event for Romanians and it received significant media coverage, but also in many other media publications. Some analysts argued that this success was not due to Romanian President being invited in US, but mainly due to the most recent scandal involving Trump (idea from above source):
Facing reporters, however, Trump is likely to get questions about James Comey, whom he accused of "many false statements and lies" the day after the ousted FBI director gave highly critical testimony before the Senate Intelligence Committee.
However, this subject is completely off-topic for this press conference, yet some 20% of time allocated to the questions was spent on this.
Question: Do US press conferences usually include off-topic questions?