The Polish military has established a group to assist the Lithuanian Army and U.S. Army in a recovery operation for four U.S. Army soldiers who disappeared early Tuesday during a training exercise near Pabradė, Lithuania.

The soldiers, based in Fort Stewart in Georgia, were riding in an M88 Hercules armored recovery vehicle on a scheduled maintenance mission to recover another U.S. Army vehicle in the training area when they disappeared, U.S. Army Europe and Africa public affairs in Wiesbaden, Germany, confirmed.

Hundreds of U.S. and Lithuanian soldiers and law enforcement, Lithuanian military helicopters and dive teams aided in the initial ground-based search through the thick forests and swampy terrain.

However, the soldiers have yet to be located, and the M88 Hercules was found submerged in a body of water inside the training area, located over a highly pressurized gas pipeline near Pabradė, a town north of the capital Vilnius.

Lithuanian engineers and U.S. Army soldiers pump water from a swamp to recover an Army M88 Hercules armored vehicle Thursday near Pabradė, Lithuania. (Lithuanian Armed Forces)

Deputy Prime Minister of Poland Władysław Kosiniak-Kamysz confirmed on X a task force of several dozen Polish soldiers with heavy equipment and frogmen were “urgently” heading to Lithuania to help.

“We are responding to a request from our allies #StrongerTogether,” Kosiniak-Kamysz wrote in the post.

The country, also a member of NATO, has reportedly feared talks between Russia and Ukraine could end in a settlement that would allow Russian President Vladimir Putin to threaten the region.

U.S. soldiers gather near military and other vehicles parked at a training range in Pabradė, Lithuania, Thursday.  (AP Photo/Mindaugas Kulbis)

Lithuanian officials said they are in touch with U.S. Ambassador Kara C. McDonald and U.S. Army personnel.

“We are leveraging every available U.S. and Lithuanian asset to coordinate and provide the required resources for this effort,” U.S. Army Maj. Gen. Curtis Taylor, the commanding general of 1st Armored Division, wrote in a statement.

The rescue mission has now turned into “search and recovery efforts,” according to a statement from U.S. Army Europe and Africa.

“We are incredibly appreciative of the dedicated and professional efforts of our Lithuanian allies in ensuring the safety of U.S. personnel,” Taylor added. “They have worked tirelessly alongside us over the last 48 hours, and we continue to be grateful for their support.” 

Recovery efforts continued Thursday for four missing U.S. soldiers near the spot where their Hercules armored vehicle was found submerged at a training range in Pabradė, Lithuania. (AP Photo/Mindaugas Kulbis)

The U.S. Army’s 3rd Infantry Division is keeping the soliders’ families updated on the search.

“This tragic situation weighs heavily on all of us, and we’re keeping the families, friends and teammates of our soldiers and recovery team in our thoughts and prayers,” Taylor wrote. “We want everyone to know we will not stop until our soldiers are found.”

President Donald Trump told reporters Wednesday he had not been briefed about the missing soldiers.

The training site is less than 6 miles from Belarus, a Russian ally since its independence from the Soviet Union in 1990.

Military road equipment at a training range in Pabradė, Lithuania, Thursday.  (AP Photo/Mindaugas Kulbis)

Lithuania, a Catholic country, will be organizing a joint prayer Sunday at its main church, the capital cathedral, and will host a mass for the missing soldiers.

The White House and Fort Stewart did not immediately respond to Fox News Digital’s request for comment.

The Associated Press and Fox News Digital’s Stephen Sorace contributed to this report.