The U.S. and Poland have signed an agreement to enhance the two nations' military cooperation, President Trump announced alongside Poland's President Andrzej Duda at the White House on Wednesday. The U.S. is looking to send at least 1,000 troops already in Europe to Poland.

The announcement comes as Poland is buying U.S. F-35 fighter aircraft, a fact Mr. Trump decided to celebrate with an F-35 flyover at the White House. But no alert was sent to D.C. residents and workers about the planned flyover, causing some concern and confusion as the fighter plane soared through restricted airspace.

The details of the new military cooperation agreement have not been released.

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"As stated in the joint declaration, the United States and Poland continue to enhance our security co-operation," Mr. Trump told reporters during a press conference in the White House Rose Garden. "Poland will still provide basing and infrastructure to support military presence of about 1,000 American troops. The Polish government will build these projects at no cost to the United States — the Polish government will pay for this."

U.S. President Donald Trump addresses a joint news conference with Poland's President Andrzej Duda in the Rose Garden at the White House in Washington, U.S., June 12, 2019. Leah Millis / REUTERS

In a press conference with Mr. Trump, Duda said the agreement means the U.S. will have an increasing military footprint in his country. The intent to increase the U.S. presence in Poland comes as Russia poses a threat to its much smaller neighbor.

"They get hurt, unfortunately, too often, right? Too often," Mr. Trump said of Poland on Wednesday. "They are in the middle of everything. When bad things happen, it seems Poland is the first one that is in there and it is unfortunate."

When Mr. Trump and Duda met in September, the leaders brought up the possibility of permanent U.S. military bases in Poland, something Duda believes would help deter Russian influence in the region. At the time, Duda said he wanted the proposed military base in Poland to be called "Fort Trump," to which Mr. Trump nodded.

Mr. Trump also told reporters Wednesday that he will meet with Russian President Vladimir Putin and Chinese President Xi Jinping on the sidelines of the G20 summit later this month.

Pressed on his deadline for negotiations with China, Mr. Trump eventually admitted to a reporter that he has no deadline.

"My deadline is what's up here," he said, pointing to his head.

He also declined to discuss the contents of a letter he announced on Tuesday that North Korean leader Kim Jong Un had given to him, only reiterating that the letter is beautiful.