South Korea's intelligence agency says North Korea could be preparing to launch an intercontinental ballistic missile to protest a summit between the United States, South Korea, and Japan due to take place this week.

The National Intelligence Service presented its analysis at a closed-door meeting of a parliamentary committee on Thursday.

According to a lawmaker who attended the session, the intelligence agency said the North could conduct provocative military actions, including launching an ICBM, to coincide with the three-way summit in the United States this Friday, or the start of US-South Korean joint military drills next Monday.

The agency cited the increased activity of vehicles at a launch site and at a factory for liquid fuel.

It also told the parliamentary committee that North Korea could launch a spy satellite at the end of August or early September, to celebrate the 75th anniversary of the country's founding on September 9.

North Korea's first attempt to launch a military spy satellite in May ended in failure.

The agency explained to the parliamentary meeting that North Korean leader Kim Jong Un has made it a priority to conduct a launch during the second half of this year.