Washington (CNN) Negotiations between the US and South Korea on dividing the cost for maintaining US troops on the Korean peninsula ended abruptly, the two countries announced Tuesday.

The sudden end to the talks, which were in their third round, comes amid renewed tensions between the allies after President Donald Trump hiked the price tag for US forces roughly 400% for 2020, a move that frustrated Pentagon officials and deeply concerned Republican and Democratic lawmakers.

The new $4.7 billion price tag also angered Seoul, which has successfully negotiated the cost sharing agreement with the US for decades and is dealing with newly heightened tensions with North Korea.

James DeHart, the chief negotiator for the US, said at a press briefing that the US delegation came "with open minds, and even prepared to adjust stance as needed in order to move towards a mutually acceptable agreement," but that the South Korean team's proposals were not responsive to US' "fair and equitable burden-sharing."

'Time to reconsider'

"We cut short our participation in the talks today in order to give the Korean side some time to reconsider and I hope to put forward new proposals that would enable both sides to work towards a mutually acceptable agreement in the spirit of our great alliance," DeHart added.

South Korea's chief negotiator Jeong Eun-bo, in his separate press briefing, said that Tuesday's negotiation could not proceed as planned, as the US team not only demanded a significant increase in burden for South Korea, but also added a new category.

"We couldn't conduct the talk as plans as the US team left the venue," Jeong said. "We maintain our current stance that the cost division (between the US and South Korea) needs to be decided based on the Special Measures Agreement frame in which we have agreed for the past 28 years."

At a press conference in Manila Tuesday, Secretary of Defense Mark Esper reiterated the statement he made earlier in the week that South Korea is a wealthy country and should shoulder more of the defense partnership costs. Esper also said he would not comment on Tuesday's negotiations as they were being handled by the US State Department.

Last week, the secretary was in South Korea to navigate renewed threats from North Korea and the newly heightened strain in the alliance with Seoul following Trump's price hike. Pyongyang recently threatening to step up its weapons development, deepening Seoul's anxiety.

North Korea has already launched 24 missiles this year, each a violation of UN resolutions, to match the country's previous annual record for firing off projectiles that threaten South Korea and Japan, according to Bruce Klingner, a senior fellow at the Heritage Foundation.

On Monday, North Korea said it is not "interested" in having "useless" meetings with the US, a day after Trump tweeted "See you soon!" to North Korean leader Kim Jong Un and the US announced it would postpone joint military exercises with South Korea that Pyongyang had strenuously opposed.

The US-South Korea cost sharing agreement has been in place for decades and, until Trump, was renegotiated every five years. During the 2016 campaign, candidate Trump declared that he would pull US troops from the peninsula if he didn't get 100% compensation for their presence.

Last year, when the Special Measures Agreement came up for negotiation, Trump asked for a 50% increase from Seoul. Ultimately, the two sides agreed South Korea would pay 8% over the prior year's cost, but that the agreement would be renegotiated yearly.

This year, Trump raised the asking price from approximately $1 billion to $5 billion before being convinced by officials at the State Department and Pentagon to winnow that down to the $4.7 billion the country was eventually asked to pay, according to a congressional aide and the administration official.