Buhari is currently in London for a holiday, and medical checks.
His absence has sparked controversy, with some criticism decision of the president to seek medical treatment in a foreign country.
But speaking with Channels Television on Tuesday, Shehu said Buhari was looking forward to returning home, and that he would come back “anytime from now”.
“As a matter of fact, we should be getting ready to see the president in fresh and that will be soon as possible,” he said.
“The president is looking to being home to be with his people. I don’t think he is enjoying an extended vacation outside the country.”
When asked whether the results of those tests were conducted, Shehu said he had no information.
“We have no information on that (test results). If he had received them, he would have been on the plane back home,” he said.
Shehu also spoke on the telephone conversation between Buhari and President Donald Trump.
He described as undiplomatic, the request that the audio containing the conversation should be released.
Shehu said releasing the audio would be highly unethical and against modern day civilization.
“I don’t think it is permitted in international diplomacy. I think if we had recorded Mr Trump in this conversation, it would have offended our diplomatic relations,” he said.
“I think the Americans themselves would not have recorded this conversation of president to president.”
Shehu said the presidents did not have enough time to discuss other continental and international issue, however, expressed optimism that the conversation would boost the bilateral relations between Nigeria and the US.
“Well, there wasn’t enough time to talk about everything. I think the point at what will follow is in the invitation that President Trump has extended to our president to come over,” he said.
“That is the kind of opportunity that was presented to Nigeria put all the issues on the desk.
“As for their immigration policy, I think our president has been clear about one thing- the choices made by the Americans as to who to lead them in this case, Mr Trump, is entirely their own choice.
“We have no business interfering with their domestic affairs. As to the countries that have been barred, it has been clearly specified and Nigeria did not feature in the list.”