The move comes as analysts are seeing Moscow’s rising pressure on Minsk to increase the satellite nation’s involvement in the Russian invasion of Ukraine.

Lukashenko made the announcement during the authoritarian leader’s meeting with his Russian counterpart, Vladimir Putin, during the latter’s Dec. 19 visit to Minsk.

“Today, we put on combat duty the S-400 complex, which you handed over to Belarus, and, most importantly, the Iskander complex, which you also, having promised it six months ago, handed over to us,” Lukashenko said, as quoted in a statement released by the Russian president’s office.

Lukashenko has long called on the Kremlin to provide his regime with Iskander missile systems. This would allow the Belarusian armed forces to expand their attack range from about 300 km (186 miles) to 500 km (311 miles), he has argued.

The distance between Minsk and Warsaw, the capital of NATO member state Poland, which has maintained strained ties with Belarus, is about 546 km (339 miles).

Last February, the Belarusian government organized a referendum which enabled the authorities to modify the constitution’s article describing the nation as a “nuclear-free zone” and a “neutral” state. The vote, which international organizations have broadly dismissed as rigged, allows Russia to deploy additional nuclear weapons along NATO’s eastern flank.

Meanwhile, the Institute for the Study of War, a U.S. think tank, said in a recent analysis that “Lukashenko uses the rhetoric of defending Belarusian borders against the West and NATO in an effort to avoid participating in the Russian invasion of Ukraine.”

Lukashenko had used similar hints about the possible deployment of nuclear weapons in Belarus on Feb. 17 in the context of claimed Western aggression, analysts wrote.

The two countries “continue to develop the plan to bolster Polish–United States military ties and United States defense and deterrence capabilities in Poland. These capabilities presently include approximately 4,500 rotational United States military personnel. As noted, this enduring presence is expected to grow by approximately 1,000 additional United States military personnel in the near term,” according to the declaration.

The partners have determined six locations for this designed enhanced military presence. Poznań, in western Poland, is to host the Division Headquarters and the U.S. Army area support group. Drawsko Pomorskie, in the country’s northwest, will host the primary Combat Training Center for joint use by the Polish and U.S. Armed Forces. Wrocław-Strachowice, in southwestern Poland, is to host the U.S. Air Force aerial port of debarkation, and Łask, in the country’s central part, will host the U.S. Air Force remotely piloted aircraft squadron. Powidz, in western Poland, is to host a combat aviation brigade, a combat sustainment support battalion, and a special operations forces facility, while Lubliniec, in the country’s south, will host a special operations forces facility, according to the document.

Warsaw and Washington are also in dialogue about “the most suitable location in Poland for an armored brigade combat team,” the declaration says.

Warsaw has been seeking a permanent U.S. military presence in Poland, dubbed “Fort Trump,” amid rising security concerns over Russian activities in the region. As part of these efforts, the Polish government offered to earmark at least $2 billion toward the project under which the U.S. would establish a military base in the country.

Last June, Duda met with Trump in Washington to discuss the initiative and sign a joint declaration on defense cooperation regarding U.S. force posture in Poland.

Following an April 28 meeting with U.S. Defense Secretary Jim Mattis in Washington, Polish Defence Minister Mariusz Blaszczak said he was “an optimist regarding an increase of U.S. military presence in Poland.”

“The decisions on this matter are moving in a good direction,” Blaszczak said, as quoted in a ministry statement.

The document, titled “Proposal for a U.S. Permanent Presence in Poland,” was obtained by local news site Onet.pl, which first broke the news. It was distributed to U.S. government institutions, Congress and some of the leading U.S. think tanks, according to information obtained from the ministry.

The ministry did not officially release the document; however, in a statement issued to local journalists, it said it was not classified and was developed “as part of the activities performed to deepen [Poland’s] defense cooperation with the U.S., including increasing the presence of U.S. forces in Poland.”

“The Government of Poland will offer significant funding for this action … as it is important to share the burden of defense spending, make the decision more cost-effective for the U.S. Government, and allay any concerns for Congress in uncertain budgetary times,” the document states.

“This proposal seems rational because the U.S. administration has been sending signals that it wants its European allies to take over a larger share of the financial burden for NATO’s strengthened presence in this part of Europe,” Tomasz Smura, the head of the research office of the Warsaw-based think tank Casimir Pulaski Foundation, told Defense News.

“The Polish side aims to convince the U.S. that at least the nonpolitical costs of such a move would be minimized. This document provides some very general information, and it outlines the infrastructural costs that would be paid for by Warsaw. Some of these costs would be covered by funds acquired from the European Union and NATO.”

The Russian factor

The move is likely to trigger a bellicose reaction by Russia, which has opposed various initiatives to expand U.S. military presence in Eastern Europe. In 2014, Moscow launched a military intervention in Poland’s neighbor Ukraine. Since then, Russia has occupied parts of the country, including the Crimean Peninsula.

As a result, numerous member states from the region have called on NATO to deploy additional troops to Eastern Europe amid increased concern over potential Russian aggression.

Poland has also intensified efforts to upgrade its defense capabilities. On March 28, Warsaw signed a letter of offer and acceptance with the U.S. to acquire Raytheon’s medium-range Patriot system. The acquisition, developed under the Wisla program, is worth $4.75 billion, according to the ministry. The purchase will consume a large portion of the country’s military expenditure, as for 2018, the ministry forecasts defense spending of 41.5 billion zloty (U.S. $11.2 billion).

Łukasz Kister, an independent security analyst with the Jagiellonian Institute, a Warsaw-based think tank, told Defense News it is good that Poland’s authorities are willing to safeguard Poland’s security by various means, but that co-financing the deployment of U.S. troops on Polish soil could jeopardize the country’s military modernization program.

“The proposal to pay the U.S. for ensuring our security raises doubts whether we will be able to finance the modernization of our own armed forces,” Kister said. “Outsourcing our security could deprive Poland of the necessary funds for various programs to upgrade our military capacities.”

According to the analyst, Polish authorities should put emphasis on industrial cooperation between U.S. and Polish defense manufacturers and ensure the transfer of knowledge to local plants.

“Poland cannot afford highly offensive military capabilities, and the U.S. is definitely a key partner with whom we should cooperate. But this cooperation should be placed at a different level. We should pay the U.S. for top technologies, know-how, gear and training, and not for the deployment of troops,” Kister said.

“The funds that are to be spent on the Patriot contract should also benefit Poland, providing training to Polish soldiers, allowing local plants to perform maintenance and overhaul works on this gear, and providing the Polish industry with know-how. This could also be beneficial to the U.S. manufacturer, as it would have an industrial outpost in Europe, which could service and repair this equipment.”