Washington (CNN) President Donald Trump spent roughly 10 minutes of an hourlong speech Thursday night in Indiana telling the story of how he saved nearly $999,800,000 on controversial plans to move the US Embassy in Israel from Tel Aviv to Jerusalem -- a claim he has made before in the months leading up to the facility's opening on Monday.

The administration did announce plans in February to designate a US consular facility in Jerusalem as the US Embassy but the process of building a new permanent embassy in the city will take years.

After opening the embassy next week, the US will build out additional office space at the consular facility by the end of 2019. But that space, too, will be temporary as the US works to identify a site and build a permanent embassy in Jerusalem.

"In parallel, we have started the search for a site for our permanent embassy to Israel, the planning and construction of which will be a longer-term undertaking," State Department spokeswoman Heather Nauert said in February.

But Trump once again failed to mention that distinction Thursday while telling the crowd that the US would spend only "$200,000 to $300,000" on the new embassy versus a $1 billion proposal he said he was initially presented with.

A State Department spokesperson told CNN on Friday that Nauert's statement still stands but added that they have "started the process of site selection for a permanent embassy in Jerusalem and "are looking at all sites we currently lease or own."

"We expect site selection, design, planning and permitting, and construction of a permanent embassy in Jerusalem to take seven to 10 years," the spokesperson said, adding that it is too early to assess the likely cost.

Trump says he was asked to sign a $1 billion plan to build a new embassy nearly three months ago after announcing the US would recognize Jerusalem as the capital of Israel.

"So they walk up to my desk and they give me this beautiful folder and I'm supposed to sign. I said, 'What is this?' And I'm half signed. He said, 'Sir, we are building an embassy in Jerusalem, sir.' I said, 'How much?' " Trump told the crowd on Thursday.

"They said -- I kid you not -- they said, 'Sir, $1 billion,' " he said.

According to his recollection, Trump immediately stopped signing the proposal and called his ambassador to Israel, David Friedman, who said that rather than building the embassy on a new site, he could renovate a building already owned by the US, and do it for just $150,000.

"I said, 'David, you can do that for $150,000. ... You know what, spend $200,000-$300,000 -- that's OK too,' " Trump said.

The State Department confirmed Friday that the cost of the initial modifications that were made to the interim site, allowing it to open on Monday, was under $400,000.

"As the President stated, the cost of initial modifications made to permit the embassy to open on Monday was under $400,000. We are also planning for construction of a new extension at the interim site as well as for additional security enhancements, at an additional cost. We're still assessing the final costs," a spokesperson for the State Department told CNN.

"The Arnona building from which the Embassy will initially operate opened in 2010. It is the newest and most secure US facility in Jerusalem and Tel Aviv. It has provided, and will continue to provide, consular services to American citizens and visa applicants. Those will continue uninterrupted after the May 14 opening as part of the new US Embassy," the spokesperson said.

Trump also touted the timing of the embassy's opening, joking that if he had agreed to the original proposal for a new complex, he would need an "extension on the presidency" to see the project through.

"The new embassy, I said, 'When is it going to be open?' " Trump recalled. "They said, 'Anywhere between five to 10 years.' So I said, 'Unless they give me an extension for the presidency."

"So they said five to 10 years, and you know when they say five to 10 years they really mean 15 to 20 years, right? So we open the embassy next week -- three months. Three months!" he exclaimed.

This is not the first time Trump has omitted certain details regarding plans for a US Embassy in Jerusalem: He made a similar claim in March while sitting alongside Israeli Prime Minister Benjamin Netanyahu in the Oval Office.

"We'll have it built very quickly. A lot of people wouldn't be doing it quickly like that. We're going to have it built very quickly and very inexpensively," Trump said at the time when asked about plans for the new embassy.

"They put an order in front of my desk last week for $1 billion. I said, 'A billion? What's that for? We're going to build an embassy.' I said, 'We're not going to spend $1 billion.' We're actually doing it for about $250,000. So check that out," he said.

"Now, it's temporary but it'll be very nice," Trump quickly added, turning to a visibly chuckling Netanyahu and saying, "$250,000 versus a billion dollars ... is that good?"