Romania is pushing to buy 54 Abrams main battle tanks and related equipment from the United States in a deal worth at least a billion dollars, the defense ministry said Friday.

The ministry said the latest-model tanks would help its military meet regional security challenges. Romania, a NATO member since 2004, shares a long border with war-torn Ukraine.

The sale would include ammunition and training simulators, the ministry said. It said Romania has estimated the contract as worth about $1 billion, but that Congress was notified of a higher value of $2.5 billion after it was approved by the U.S. State Department on Thursday. No timeframe for the purchase was specified.