BERLIN, June 19 (Reuters) - Germany's armed forces only have around 20,000 high explosive artillery shells left, magazine Der Spiegel wrote on Monday citing confidential defence ministry papers prepared to convince the budget committee of the need for urgent purchases.

Countries like Germany have rushed to send supplies of 155m artillery rounds used by howitzers to Ukraine in the wake of its invasion by Russia in February 2022, running down stocks for their own defence.

Germany's military needs to build up an inventory of some 230,000 shells by 2031 to comply with NATO goals to have enough artillery to withstand 30 days of intensive combat, Der Spiegel wrote.

The defence ministry did not immediately reply to a request for comment.

The ministry aims to present the budget committee with nine contracts for the accelerated purchase of artillery and tank ammunition in coming months, Der Spiegel wrote.