National Assembly Intelligence Committee Chairman Kim Kyung-hyup, center, speaks with Rep. Kim Byung-kee, left, of the main opposition Democratic Party of Korea during a meeting at the Assembly in Seoul, Thursday. Yonahp

North Korea is gauging the timing of when to conduct what would be its seventh nuclear test after completing preparations, South Korea's spy agency said Thursday.

The National Intelligence Service also said in a closed-door briefing to lawmakers that there were signs North Korea could launch an intercontinental ballistic missile (ICBM) even though it is grappling with a COVID-19 outbreak.

The assessment came amid concerns that North Korea could carry out a major provocation during U.S. President Joe Biden's visit to Seoul this week for a summit with President Yoon Suk-yeol.

"It would not be abnormal for North Korea to launch a missile or conduct a nuclear test at one point, as signs (of such provocations) are detected and Pyongyang has almost completed its preparations," Rep. Kim Byung-kee of the main opposition Democratic Party of Korea told reporters.

Kim Tae-hyo, the first deputy chief of South Korea's presidential National Security Office, said Wednesday the North's preparations for an ICBM launch appear to be "imminent." (Yonhap)