The Kremlin said President Vladimir Putin visited the Kursk border area for the first time since Russian troops popped up Ukrainian forces from the region last month.
Ukrainian troops achieved one of the biggest battlefield successes in the war over three years in August 2024, invading the Kursk region. This is the first time since World War II that Russian territory has been occupied by invaders.
Since the end of 2023, Russia has mostly had an advantage on the battlefield, except Kursk.
At the height of the invasion, Ukrainian troops captured nearly 1,400 square kilometers (540 square miles) of Kursk.
Russia said in late April that it had popped up Ukrainian troops from the region.
The Kremlin said on Wednesday that during Tuesday's "work visit", Putin met with volunteer organizations in Kursk and inspected nuclear power plants in the region.
Russian state television shows Putin met with volunteers and local officials in the region, including Acting Governor Alexander Khinshtein.
Putin was accompanied by Sergei Kiriyenko, the first deputy chief of staff of the Kremlin.
The Ukrainian National Guard said on Wednesday that at least six soldiers in Ukraine were killed in a missile strike on Tuesday, and another 10 were injured.
"Internal investigations have been conducted into the incident. The commanders of the military forces have been suspended and the necessary information has been transferred to law enforcement agencies," the National Guard of Ukraine said in a statement.
In recent months, Ukraine's Sumi-Myanmar border area has been intensified. The Russian Defense Ministry said Tuesday night that it had launched a ballistic missile attack at the Ukrainian ruins.
It said in a social media post: "During the reconnaissance activities...a training camp for Ukrainian special forces."
"Based on the coordinates received, an Iskander missile strike was launched."
Russia also released footage showing what it said was a training camp in a tree forest area.
Antenna footage showed a strike that sparked a fire and rolled into the air with black smoke plumes.
Meanwhile, Russia said Ukraine intercepted 159 drones in several areas, including Moscow.
The drones targeted primarily Russian regions bordering Ukraine and were launched Tuesday night and Wednesday morning, a statement from the Ministry of Defense said.
The barrage was a ceasefire that failed to break through the three-year conflict two days after a call between Putin and U.S. President Donald Trump.
European diplomats have been urging Moscow to agree to a truce.
Ukrainian President Volodymyr Zelenskyy accused the Kremlin of stagnation in order to continue the attack.
U.S. Secretary of State Marco Rubio said Tuesday he expects Russia to propose a Ukrainian ceasefire outline within a few days, which would indicate that it is serious.