President Donald Trump has said he "can't imagine why" US hotline calls about disinfectant have risen after he suggested injecting the substance to treat coronavirus.
The governors of Michigan and Maryland on Sunday blamed the president for the spike in such calls.
Following heavy criticism from medical professionals, Mr Trump said his remarks were made sarcastically.
Disinfectants are hazardous substances and can be poisonous if ingested.
During Monday's Covid-19 news conference, a reporter noted that the state of Maryland's emergency hotline had received hundreds of calls in recent days seeking guidance about Mr Trump's comments.
"I can't imagine why," the president said, moving quickly on. "I can't imagine that."
When asked whether he took responsibility at all for the increase in calls, Mr Trump replied: "No, I don't."
Last week, the Maryland governor's office said it had issued a statewide alert warning against ingesting or injecting disinfectants following the president's remarks.
Mr Trump made the disinfectant remarks on Thursday, after an official presented the results of US government research that showed Covid-19 could be killed in minutes by bleach.
"I see the disinfectant where it knocks it out in a minute. One minute," Mr Trump said. "And is there a way we can do something like that, by injection inside or almost a cleaning?"
On Friday afternoon, Mr Trump told journalists: "I was asking a question sarcastically to reporters like you just to see what would happen."
During Monday's Rose Garden press conference, Mr Trump was also asked whether he would delay the presidential election in November.
"I never even thought of changing the date of the election," he said. "Why would I do that?"
Former US Vice-President Joe Biden, Mr Trump's presumptive Democratic opponent, said last week he thought Mr Trump would "try to kick back the election somehow".
But Mr Trump told reporters the idea was "made-up propaganda".
"I look forward to that election," Mr Trump said.
Constitutional scholars have already noted that if a president wanted to change the timing of a White House election he would be unable to do so - even in an emergency - because the date is set by Congress.
Mr Trump then took questions on a wide range of subjects, including:
- Coronavirus deaths: The president was asked if he deserved to be re-elected given the number of Americans who had died over the past six weeks - more than 55,000. He defended his administration and said it had done an "unbelievable" job during the crisis
- China: Mr Trump suggested the US may seek damages from China for the spread of the coronavirus. "We believe it could have been stopped at the source," he said, adding that there were "lots of ways" to hold China accountable. It comes days after the state of Missouri said it was suing the Chinese government over the outbreak
- Schools: The president said state governments should "seriously consider" reopening public schools before the end of the academic year in May. But officials have warned that doing so could pose major health risks. "Even if it's for a very short period of time, I think it would be a good thing," Mr Trump said
- North Korea: When asked about speculation over North Korean leader Kim Jong-un's health, Mr Trump said he had "a very good idea" about his condition. "I can't talk about it now. I just wish him well," he said. There have been unconfirmed rumours about Mr Kim's health ever since he missed a public event earlier this month
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