WASHINGTON — President Trump signed a $700 billion defense policy bill Tuesday, saying the United States military "has got to be perfecto." But less than three hours later, he pointed out the bill's imperfections in a signing statement.

Among them: A variety of provisions lawmakers included to force a more aggressive U.S. policy toward Russia.

Those provisions, Trump said in his signing statement, raise constitutional concerns – and "could potentially dictate the position of the United States in external military and foreign affairs" and interfere with his ability to conduct diplomacy.

The bill passed by Congress contains several provisions specifically targeting Russia. It restricts military cooperation with Russia, prohibits the United States from recognizing Russia's legal right to the disputed Crimea peninsula, and requires the military to "develop and implement a comprehensive strategy to counter threats by the Russian Federation" — including Russia's use of disinformation, social media and support for political parties.

Trump has himself expressed a willingness to work with Russia and touted his good relationship with its president, Vladimir Putin.

His position on Russia has been closely watched as a Special Counsel Robert Mueller investigates whether members of the Trump campaign colluded with Russia during the 2016 presidential election. That investigation has resulted in two guilty pleas and two indictments of senior campaign and transition officials.

Presidents use signing statements to explain their positions or urge Congress fix flaws in what they consider an otherwise worthy bill. But they can also be controversial because presidents use them to raise constitutional objections to a bill, instructing agencies to implement the law consistent with their own understanding of presidential powers.

The signing statement Tuesday contained objections to more than 40 provisions in the defense bill, which passed both houses of Congress with large, bipartisan majorities.

"Protecting our country should always be a bipartisan issue, just like today's legislation," Trump said at a White House signing ceremony surrounded by Pentagon brass, giving no hint of any objection he had to the bill.

One such provision would withhold funding from the White House Communications Agency unless the president submits a report to Congress on cybersecurity. Trump called it an "unprecedented and dangerous funding restriction."

The WHCA is a $45 million military agency that helps facilitate presidential communications to the public, especially when traveling. "The Congress should not hold hostage the President's ability to communicate in furtherance of the nation's security and foreign policy," Trump said.

It was the seventh signing statement of Trump's presidency. Trump has previously used signing statements to put his interpretation on a government-wide spending bill, a Russia sanctions bill, and a congressional resolution condemning hate groups after right-wing demonstrators clashed with counter-protesters in Charlottesville, Va. this summer.

The constitutional objections contained in Trump's signing statements are sometimes at odds with his political positions. On Tuesday, he objected to a congressional effort to reform the process of vetting foreign investments in the United States, for example, even as he's called for an investigation into the Obama administration's approval of a uranium deal with Russia.

And in a nuanced departure from his previous position on Guantanamo Bay, Trump objected to a part of the law that forbids the president from closing the U.S. military prison in Cuba, where suspected terrorists captured overseas have been held since 2001.

"I fully intend to keep open that detention facility and to use it for detention operations," he said. But he also repeated "the longstanding position of the executive branch" that the law could be unconstitutional and "could, in some circumstances, interfere with the ability of the United States to transfer a detainee who has been granted a writ of habeas corpus."

Trump had objected to a similar provision in a spending bill in May, but his new objection suggests an openness to transfer prisoners to the United States for civilian trials.

White House press secretary Sarah Huckabee Sanders said the president signed the bill because it increased the size of the military for the first time in seven years, and gave troops their biggest pay raise in eight years.

"To put it into historical context, it authorizes one of the largest defense spending increases since the days of Ronald Reagan," she said. "In signing this bill today, the president once again made it clear that we are serious about enhancing military readiness."

Sanders also defended Trump's record on Russia. "I think we’ve been very hard on Russia from the beginning," she said. "We’ve done things to put pressure on Russia, asking them to engage in a bigger and greater way on some of the common enemies that we face."