The United States continues to have concerns about the Scottish independence referendum as Thursday's vote approaches, with the White House aides stating Monday that Washington would respect the outcome of the vote but would prefer the United Kingdom to remain "strong, robust and united."

On Thursday, Scots will vote whether to split from the United Kingdom and become an independent country, Reuters reported. Since the formation of a separate Scottish military would cause disruption to NATO defenses, U.S. would rather have the nation be a part of UK, a variety of experts said.

Speaking to reporters at the daily press briefing on Monday, White House Press Secretary Josh Earnest said it was up to the people of Scotland to decide their fate in this week's referendum, but that the U.S. has a "deep interest" in a united UK, Time reported.

"This is a decision for the people of Scotland to make," Earnest said. "We certainly respect the right of individual Scots to make a decision along these lines."

Earnest would not explicitly state the United States' opposition to efforts in creating the first independent Scotland in 307 years. "I will certainly respect their right to cast their own ballot without interference from people on the outside."

However, some elements of the U.S. government were considering what the implications of a potential independent Scotland would be on the United States' "special relationship" with the United Kingdom since the end of World War II, Earnest said.

"I suspect that there's somebody at the administration who's been thinking about that at some level," he said. "I don't know to what level it has risen."

On June 5, speaking beside British Prime Minister David Cameron at a press conference, President Barack Obama said "we obviously have a deep interest in making sure that one of the closest allies that we will ever have remains strong, robust, united, and an effective partner. But ultimately these are decisions that are to be made by the folks there."

Meanwhile, since Scotland's 307-year-old union with the rest of Britain could end in the next three days, the referendum's pro-Independence "Yes" movement has been continuously gaining momentum while closing the gap on the pro-Union "No" campaign, USA Today reported.

Officially, the Obama administration remains neutral on Scotland's choice.