German defense company Rheinmetall has requested approval to export 100 old Marder infantry fighting vehicles to Ukraine, a defense source told Reuters on Monday, in what would be the first heavy weapons shipment from Germany to Ukraine.

The company is seeking an export license for the vehicles in their current state, aiming to restore them over the coming months before shipping them to Ukraine, the source said, confirming a report in the Welt am Sonntag newspaper.

Rheinmetall's move is set to force Chancellor Olaf Scholz to take a clear position on whether heavy weapons can be sent directly from Germany to Ukraine because the Marder deal requires approval from the national security council, which is chaired by Scholz.

A Rheinmetall spokesperson declined to comment.

Scholz is facing growing criticism at home and abroad for his reluctance to deliver heavy weapons such as tanks and howitzers to help Ukraine to repel Russian attacks.

On their first visit to Ukraine since Russia invaded two months ago, the U.S. Secretaries of State and Defense on Sunday pledged additional military aid to Kyiv, including advanced weapons.

Ukrainian pleas for heavy weapons have intensified since Moscow shifted its offensive to the eastern region of Donbass, a territory seen as better suited for tank battles than the areas around Kyiv, where much of the fighting has taken place so far.

Moscow describes its actions in Ukraine, now entering a third month, as a "special military operation."