President Yoon Suk Yeol’s approval rating fell to 33.6 percent last week, a six-month low largely prompted by a skeptical public urging the president to confront the US over its recent leak of secret intelligence reports suggesting Washington may have been spying on Seoul.

Yoon’s first deputy national security adviser brushed off the damaging leak that made headlines two weeks ago, saying the US seems to have had “no malicious intent,” without offering any concrete evidence. Washington, Seoul’s biggest ally, cleared up any misunderstandings, according to Yoon’s office.

But the five-day Realmeter poll released Monday found that 63.4 percent of Koreans disapprove of Yoon’s job performance. The approval rating, at 33.6 percent, is the lowest since the third week of October last year, when it stood at 32.9 percent.

“The way Yoon officials have dealt with public doubts was a blow,” said Bae Cheol-ho, the principal researcher at the pollster, referring to the office’s handling of the matter.

In late April, Yoon will make a state visit to the US, a trip Seoul hopes will not only celebrate 70 years of relations, but openly solidify Washington’s commitment to defend its allies from North Korea’s growing nuclear threats.

Pyongyang has been carrying on weapons tests, the latest of which took place Thursday when it fired off a new solid-fuel intercontinental ballistic missile, which experts say potentially marks a significant advance in technology. The weapon fires quicker and is harder to detect than liquid-fuel missiles.