Updated Dec. 9, 2016 6:06 a.m. ET
KALININGRAD, Russia—Military maneuvering here in the Baltic region by Russia and NATO presents a challenge for President-elect Donald Trump and his commitment to America’s European allies.
The North Atlantic Treaty Organization plans to station a multinational force on its eastern flank by May as a deterrent following Moscow’s aggression in Ukraine. But already in January, a brigade from the U.S. Army 4th Infantry Division will arrive in Germany and then move to Poland—before Inauguration Day, according to U.S. military officials.
After conducting systems tests in Poland, one battalion will go back to Germany to the training center, another battalion will go to the Baltic states and one battalion will go to Romania, the officials said.
NATO military officials held an exercise last week to help plan the deployment. “There are units ready to deploy on the other side of the holidays,” U.S. Army Gen. Curtis Scaparrotti, the Supreme Allied Commander, Europe, said Wednesday.
Meanwhile, Russia has been moving in recent months to deploy new antiship missile systems, S-400 air defenses and nuclear-capable Iskander missiles to the Kaliningrad region, long its citadel on the Baltic Sea.
The exclave is now sandwiched between new NATO members Poland and Lithuania. Officials in Washington and Brussels have said the buildup is meant to test the Western alliance—a postwar mutual-defense pact that Mr. Trump raised questions about during his campaign.
State Department spokesman John Kirby last month called the deployment unwarranted and “destabilizing to European security.”
Moscow quickly fired back.
“Russian state security is the prerogative of our country’s leadership alone,” said Maj. Gen. Igor Konashenkov, spokesman for the ministry of defense. “So any claims and suggestions about where, when, what and how we need to ensure our security on our territory, keep to yourselves.”
Russian officials have described the Iskander deployment as a counterweight to missile-defense systems the U.S. has put in Romania and plans to install in Poland. Washington says the systems are to guard against missiles fired toward Europe from countries such as Iran, but Russia sees them as a threat.
Asked in November about the missile deployment, Kremlin spokesman Dmitry Peskovwas quoted by the news agency Interfax as saying: ”NATO is an aggressive bloc, so Russia is doing everything necessary to respond to that.”
NATO Secretary-General Jens Stoltenberg described the alliance’s moves as measured.
“We don’t want confrontation,” he said Wednesday. “But we have to respond when we see a more assertive Russia acting the way that they have done in Ukraine and the military build up close to our borders.”
Despite the heated rhetoric, President Vladimir Putin said Russia is “ready to cooperate” with the Trump administration. “It is important to normalize [ties] and begin to develop a bilateral relationship,” he said on Dec. 1.
During his campaign, Mr. Trump expressed admiration for Mr. Putin’s leadership and said the U.S. and Russia could cooperate more on fighting terrorism.
Meanwhile, his comments about NATO’s collective defense obligations have raised hackles among U.S. allies. In an interview with the New York Times, Mr. Trump said that if Russia attacked the Baltic states, he would consider coming to their defense only after reviewing “if they have fulfilled their obligations to us.”
Kaliningrad, called Königsberg when it was part of Prussia and Germany, traces its origins to a fortified medieval town. It was blasted into ruins during World War II, pounded first by British bombers and then by a final Soviet assault in spring 1945.
The Soviets expelled the German population and renamed it after a Communist revolutionary. Much of the center was rebuilt with concrete-block housing that left little trace of its prewar splendor.
Today, Kaliningrad wants to project an image of a trading center and window to Europe.
“Kaliningrad is a very peaceful city,” said deputy mayor Artur Krupin. “Residents of Kaliningrad are very peaceful and good, they want in the best sense of the word to represent Russia’s interests within the European Union. They want to invite guests.”
The walled fortifications that remain in the city, he added, “have lost their original meaning.”
Mr. Krupin described Kaliningrad as “a platform for international dialogue” because of its proximity to markets in Eastern Europe. Local residents say economic ties have been set back by Russia’s chilly relations with NATO members, however.
In July, the Polish government did away with visa-free travel for Kaliningrad residents and neighboring Ukrainians to Polish border regions, citing security reasons ahead of a NATO summit and a visit by Pope Francis.
While Poland has since reinstated local border traffic with Ukraine, it decided not to with Kaliningrad, ending a brisk suitcase trade in household goods.
Asked about the matter in September, Polish Interior Minister Mariusz Blaszczak said the exclave was heavily militarized and has a new governor close to the Kremlin.
Russia’s economic crisis has also hit the region, which depends on tourism in addition to manufacturing and trade. A vendor selling amber souvenirs in the Baltic resort of Svetlogorsk said most visitors were retirees with little to spend because the Russian government hadn’t adjusted pensions in line with inflation.
“I hope there is a revolution!” he said. “Nothing will change as long as these guys are in charge.”
Despite saber-rattling over the region, however, little anti-Americanism is in evidence. Kaliningrad even has a restaurant downtown called Obama Pizza. Its slogan: Yes We Eat.
“We’re not changing it to Trump,” the pizzeria’s manager said.
—Julian E. Barnes in Brussels contributed to this article.
Write to Nathan Hodge at email@example.com