American Rare Earths (ASX:ARR) has received the final payment of AU$1million, along with accrued interest of AU$42,246, from Cobalt Blue Holdings (ASX:COB) under the terms of the promissory note issued to the company in January 2020, according to a Thursday filing with the Australian bourse.

Proceeds will be used to develop the company's Halleck Creek project in the US, the filing said.