Addressing a press conference in Davao City after his return from a state visit to China, Duterte said:
"It is not severance of ties. You say severance of ties, you cut the diplomatic relations. I cannot do that.
"Why? It is in the best interest of my country that we maintain that relationship. Why? Because there are many Filipinos in the United States. Well, Americans of Filipino ancestry.
"Why? Because the people of my country [are] not ready to accept. I said separation -- what I was really saying was separation of a foreign policy. "
There was widespread shock after Duterte announced
his "separation" from the United States, suggesting he would cut both economic and military ties in favor of moving closer to China.
"America has lost now. I've realigned myself in your ideological flow," Duterte told business leaders Thursday in Beijing.
"And maybe I will also go to Russia to talk to Putin and tell him that there are three of us against the world: China, Philippines and Russia. It's the only way."
In a statement Friday, Duterte's office said the Philippines had no intention to renege on treaties or agreements with allies.
The President's comments were "an assertion that we are an independent and sovereign nation, now finding common ground with friendly neighbors with shared aspirations in the spirit of mutual respect, support and cooperation," the statement said.
Trade Minister Ramon Lopez told CNN that the Philippines "would not stop trade and investment with the US."
"(Duterte) has decided to strengthen further and rekindle the ties with China and the ASEAN region," Lopez said, referring to the Association of Southeast Asian Nations.
White House spokesman Josh Earnest described Duterte's comments as "personal," "offensive" and "confusing."
The US Embassy in Manila blasted Duterte's comments as "creating unnecessary uncertainty."
"We've seen a lot of this sort of troubling rhetoric recently, which is inexplicably at odds with the warm relationship that exists between the Filipino and American people and the record of important cooperation between our two governments," embassy spokeswoman Molly Koscina said in a statement.
The United States will honor its alliance commitments and treaty obligations, and expects the Philippines to do the same, she added.
The Philippines is a key US ally in the region, and Washington supported former President Benigno Aquino's efforts to gain international recognition for Manila's claims to South China Sea territory illegally occupied by China.
Beijing rejected a recent international court ruling in Manila's favor and has long called for bilateral negotiations in which other parties do not participate.
In a statement, China's Ministry of Foreign Affairs praised Duterte's willingness to address "territorial and jurisdictional disputes by peaceful means ... through friendly consultations and negotiations by sovereign states directly concerned."
'Maybe he's only joking'
More than 2.6 million Filipinos live in the United States.
Trade in goods between the two countries topped $18 billion last year
, and American companies have invested more than $4.7 billion in the Philippines. The United States also accounts for roughly a third of the $17.6 billion that Filipinos working overseas have sent home this year.
In Manila, many greeted the news with shock.
"Maybe he's only joking," saleswoman Marisa Laguitan, 59, said.
"America is very friendly and a very long (term) friend of Filipinos."
Ian Duly, 34, said he had nothing against the United States, but "it's about time for a change."
"I believe in Duterte," he added. "It's about standing up for your people."
Speaking to CNN Philippines, one call center worker worried about the effect the move could have on her industry.
"What if BPOs disappear in the Philippines? We won't have a job," she said, referring to business process outsourcing.
More than 1 million
Filipinos work in call centers and data processing, servicing mainly the United States. The government expects the market to generate upward of $25 billion in revenue this year
Lopez, the trade minister, dismissed concerns that Duterte's shift would endanger the country's economy.
"What we are saying is that there will be less dependence just on one side of the world," he told CNN.
"As you know, we have been strong partners with the US so it's basically just trying to balance the partnership and also strengthening this side of the world, specifically with China."
He said Duterte was pursuing an independent and "more sovereign" foreign policy, adding that the US-Philippines relationship was strong and "cannot just be eliminated."
Duterte's opponents at home were damning, however.
"(He) has a really inflated, if not delusional, view of himself as a strongman at the level of China and Russia's leadership," Sen. Leila de Lima, a longtime Duterte, said in a statement.
Former Foreign Minister Albert del Rosario warned of cozying up to a country such as China that doesn't share "our core values of democracy (and) respect for human rights."
"Casting aside a longtime reliable ally to hastily embrace an aggressive neighbor that vehemently rejects international law is both unwise and incomprehensible," he said in a statement.