President-elect Donald Trump, his transition team and the North Atlanta Treaty Organization (NATO) are reportedly being tested by Russia and its President Vladimir Putin as it continues to reinforce troops and missile systems in the Kaliningrad exclave in the Baltic region, the Wall Street Journal reported Friday.

U.S. military officials told the Journal that while NATO has plans to send a multinational force to the east in response to Russia’s actions in Ukraine in May, the Army 4th Infantry Division will be in Germany and Poland in January before Trump takes office. From there, the U.S. force will disperse one battalion back to Germany, one will stay in the Baltic States and a third will head to Romania.

The test for Trump lies in Kaliningrad’s geographic position — nestled directly between NATO members Lithuania and Poland to the southeast of the Baltic Sea — and Russia’s recent air and missile defense build-up in the region.

Last month, a top Russian lawmaker said the military would further deploy its S-400 air missile defense system and ballistic Iskander missiles to Kaliningrad, which Russia took control of from Germany after World War II, in order to strengthen its western border.

The movement put major European cities like Berlin and countries like Poland and Sweden in danger of attack since the S-400 has a range of 300 miles.

Trump’s campaign rhetoric regarding NATO will again take center stage as Putin and his government feel out the first-time elected official. During an interview with the New York Times, Trump was asked what he would do if Russia crossed over into NATO allies and said he had reservations about coming to the aid of countries who “aren’t paying their bills.”

“I don’t want to tell you what I’d do because I don’t want Putin to know what I’d do. I have a serious chance of becoming president and I’m not like Obama, that every time they send some troops into Iraq or anyplace else, he has a news conference to announce it,” Trump said. “We have many NATO members that aren’t paying their bills.”

Trump added: “You can’t forget the bills. They have an obligation to make payments. Many NATO nations are not making payments, are not making what they’re supposed to make. That’s a big thing. You can’t say forget that.”

Along the campaign trail, Trump was accused of perhaps being too cozy or indirectly friendly with Putin. Those accusations were magnified following hacks perpetrated by Russia against the Democratic Party and seen as pro-Trump. The president-elect, Now, who is set to take the Oath of Office in about six weeks, has denied any ties to Russia both before and after he won the election.