With less than a month left before the hugely-anticipated talks between US President Donald Trump and North Korea's leader Kim Jong-un in Singapore, the US top diplomat has indicated that any deal paving the way for a nuclear-free Korean peninsula will have to include certain US safeguards allowing Kim to stay in power.

"We will have to provide security assurances to be sure. This has been the trade-off that has been pending for 25 years,"Pompeo told 'Fox News Sunday.' Pompeo was speaking to Fox's Chris Wallace just a few days after he returned to the US from his second meeting with Kim, during which they were supposed to thrash out the details of the Trump-Kim summit on June, 12.