Dhaka, Oct. 8 -- US President Donald Trump has said he "could've done very bad things" to Hillary Clinton and former presidents Joe Biden and Barack Obama, saying he chose not to because of his respect for the presidency.

Trump made the remarks during an Oval Office event on Wednesday, promoting his "Trump Accounts" for children after returning to Washington, DC from campaign events ahead of the November midterm elections, UK-based publication The Independent reports.

The three senior Democratic figures are frequent targets of Trump's attacks.

A reporter asked Trump about his previous claim that Democrats would impeach him if they regained control of Congress in November.

"For what?" the reporter asked.

"They don't know," Trump said ...