Satellite imagery has reportedly captured new indications that North Korea appears to be preparing for a missile launch.

According to the Voice of America(VOA) on Tuesday, the recent imagery of the Sunan airfield near Pyongyang showed new concrete foundations.

The imagery, taken by Planet Labs on Saturday, showed two concrete foundations designed to support a transporter erector launcher(TEL) used for missile launches.

The VOA said the foundations are both 50 meters wide, with the bigger one 220 meters long and the smaller one 100 meters long.

North Korea conducted missile launches on February 27 and March 5 at the site to test what South Korean and U.S. officials believe is a new intercontinental ballistic missile(ICBM) system.

Bruce Bennett, a defense analyst at the RAND Corporation research center told the VOA that the TEL gets extraordinarily heavy if the missile is fully fueled, requiring a strong foundation to launch a big missile such as an ICBM.