WASHINGTON, July 18 - Ukrainian forces have a “significant amount of combat power” that hasn’t yet been committed to the war, the top U.S. military officer said Tuesday, saying Kyiv is conserving some of its tactical effort while troops slowly work their way through deadly Russian minefields.

Speaking to reporters after defense leaders from around the world met to discuss Ukraine’s military needs, Army Gen. Mark Milley was asked about the slow pace of Ukraine’s offensive to take back territory seized by Russia. He said Ukraine will decide when to use the combat power and complex training the U.S. and allies have provide. He flatly dismissed suggestions the offensive is failing.

“It is far from a failure, in my view. I think that it’s way too early to make that kind of call,” said Milley, chairman of the Joint Chiefs of Staff, The Associated Press reported. “Right now they are preserving their combat power. And they are slowly and deliberately and steadily working their way through all these minefields, and it’s a tough fight. It’s a very difficult fight.”

Milley and Defense Secretary Lloyd Austin met with reporters at the close of the 14th meeting of the Ukraine contact group, which is made up of the defense and military leaders from more than 50 nations. The group met virtually Tuesday to discuss how to continue to meet Ukraine’s need for weapons and training.

Austin said he asked allies to “continue to dig deep into their military stocks,” particularly for ammunition, which Ukraine urgently needs.

The officials announced no new military aid, but the U.S. this month agreed to provide thousands of cluster munitions to Ukraine, and included them in an $800 million aid package. The munitions, which are being taken from Pentagon stocks, began arriving in Ukraine for the war effort last week. Overall the U.S. has provided more than $40 billion in aid to Ukraine.

Austin and Milley’s comments came as tensions between the U.S. and Russia continue to spike. There has been a recent series of close calls between Russian and U.S. military aircraft over Syria, including a Sunday incident when a Russian fighter jet flew very close to a U.S. surveillance plane that was carrying a crew of four.

The Russian Su-35 flew so close to a U.S. MC-12, that it forced the American plane to go through the turbulent wake, putting the crew’s lives in danger.

Lt Gen Alex Grynkewich, the commander of U.S. Air Forces Central, said Tuesday that “these actions against a manned aircraft represent a new level of unsafe and unprofessional actions by Russian aircraft operating in Syria” He said flying into the turbulance reduced the U.S. crew’s ability to safely operate their aircraft. The MC-12 is a twin engine turbo prop.

Asked about the recent incidents, Milley said the U.S. is “monitoring it very closely. As to the reason why the little bit of an uptick, I’m not really certain. We’ve got analysts trying to figure that out.” He added that U.S. forces in the region have the capabilities and the authorities they need to protect themselves. (ap/ez)