The United States was closely engaged with the armed forces of Ukraine ahead of the Kharkov counteroffensive, providing Kiev's military with intelligence in the buildup to the operation, a senior official in the US Department of Defense, cited by Sputnik, said on Monday.

"We're in close contact with and conversation with the Ukrainian military. They had multiple options. We certainly provide them with information on conditions, but in the end, this is a Ukrainian choice," the senior Pentagon official said in response to a press inquiry regarding Washington's involvement in the planning for the counter-offensive.

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The official then went on to underline how his country would continue providing training for Ukraine's military on modern weapon systems supplied to the country by the West as the war unfolds.

"The United States is already has been for a couple of months now been training Ukrainian forces on how to operate some of the newer, more modern capabilities that we have been supplying to Ukraine," the official said.

The training also includes helping Kiev's forces with the "maintenance, repair, and sustainment of those capabilities. So, we would certainly continue that area of training," he noted.

Furthermore, the Pentagon official highlighted how some countries started investing and working on providing basic training for Ukrainian soldiers and the leaders of the Contact Group member states discussed the next steps in their progression during their meeting at Ramstein a few days ago.

Additionally, the US official stressed that his country decided to move forward to procure air defense systems for Ukraine, including the National Advanced Surface-to-Air Missile System (NASAMS).

In a statement, US President Joe Biden had stated that the newly instated $2.98 billion military assistance will allow Ukraine to acquire air defense systems, artillery systems and munitions, drones, and other equipment “to ensure it can continue to defend itself over the long term.”

The military aid package, according to a Bloomberg report which cited 2 US officials, includes six NASAMS air defense systems as well as "Vampire" drone systems.

Earlier in July, Biden had promised Ukraine two NASAMS and in early August the US Department of Defense said that they will be delivered within two to three months. 

"The United States has now moved forward to procure for Ukraine through USAI [Ukraine Security Assistance Initiative] air defense systems such as NASAMS," the Pentagon official told the press briefing.

Furthermore, the package also includes funding for training, preservation, and sustainment of the provided equipment, as well as 245,000 rounds of 155mm artillery ammunition, 65,000 rounds of 120mm mortar projectiles, Puma unmanned aerial systems, support equipment for Scan Eagle systems, and laser-guided rocket systems.

Despite Washington providing information to Kiev about Russian command posts, ammunition depots, and other potential targets, Ukrainian officials had been hesitant to disclose operational plans to their US counterparts earlier in the conflict, fearing that doing so "could highlight weaknesses and discourage continued American support," based on the information reported by The New York Times (NYT).

However, all changed this summer, when Kiev concluded that discussing preparations for its counteroffensive would, contrary to past fears, compel Washington to supply Ukraine with even more weapons, according to unidentified senior US officials cited by the NYT report.

Russia announced on Saturday that its forces were withdrawing from the Kharkov region that lies on the eastern front after the army had the region under its control for months.

"To achieve the goals of the special military operation to liberate Donbass, a decision was made to regroup Russian troops stationed in the Balakliya and Izyum regions, to bolster efforts along the Donetsk front," the Russian ministry of defense said in a statement. 

The drawdown of the Russian armed forces comes in light of the Ukrainian military saying they entered the town of Kupiansk in Kharkov.

The withdrawal from Kharkov to Donetsk, Moscow explained, was carried out over the course of a three-day operation conducted to minimize Russian losses. However, the leader of the Donetsk People's Republic, Denis Pushilin, said there was fierce fighting between the Russian and Ukrainian forces in the DPR.

Pushilin explained that the situation in the town of Lyman, Donetsk, was "very difficult" and that fighting had erupted in "a number of localities", particularly in the north. 

"We have no other choice but to keep Donbas and we'll succeed. We'll win of course," Pushilin stressed. 

In light of the retreat, Russian Defense Ministry spokesperson Igor Konashenkov told reporters that his country's military eliminated more than 2,000 Ukrainian fighters near Balakleya and Izyum.