In a first response to unusually harsh comments made about him by Defense Minister Moshe Ya’alon, US Secretary of State John Kerry said Wednesday that he would not let the criticism derail peace talks, and that he would “work undeterred” until an agreement was reached.

He said he and Prime Minister Benjamin Netanyahu were in regular contact “and we are both very committed” to the peace process. “We just can’t let one set of comments undermine that effort, and I don’t intend to,” Kerry said at a press conference in Kuwait.

In statements published by the daily Yedioth Ahronoth on Tuesday, Ya’alon referred to the American diplomat as “inexplicably obsessive” and “messianic” in his efforts to have Israel and the Palestinians negotiate a final status deal. The paper recounted the defense minister lambasting the proposed security arrangements drawn up by Kerry as part of the secretary’s plan, saying the proposal was “not worth the paper it is printed on” and would not provide security for Israel.

But in his response Wednesday, Kerry sounded as determined as ever to see the peace process through to its conclusion, and a confident of success.

“After five months of negotiations, I believe strongly in the prospects for peace and I know the status quo is not sustainable,” he said. “We’ve always known that as we approach the time for these difficult choices, it’s going to be difficult.”

The defense minister had also reportedly said that Kerry had “nothing to teach me about the conflict with the Palestinians. All that can ‘save us’ is for John Kerry to win a Nobel Prize and leave us in peace.”

Ya’alon’s comments were met with sharp rebukes by US officials that led the defense minister to issue a public apology Tuesday night, after a long meeting with Netanyahu. In a statement published in English and Hebrew, the defense minister’s bureau said Israel greatly appreciates Kerry’s efforts and that Ya’alon “did not intend to insult the secretary and he apologizes if the secretary was hurt by the remarks attributed to the defense minister.” He did deny or confirm making the scathing remarks.

The American administration also demanded that Netanyahu explicitly disavow Ya’alon’s comments and affirm his commitment to the peace talks, according to several Israeli media outlets.

“To question Secretary Kerry’s motives and distort his proposals is not something we would expect from the defense minister of a close ally,” White House spokesman Jay Carney said Tuesday, echoing earlier comments from State Department spokeswoman Jen Psaki.

“The remarks of the defense minister [Ya’alon], if accurate, are offensive and inappropriate, especially given all that the United States is doing to support Israel’s security needs, and will continue to do,” Psaki said in a brief statement in Rome.

“Secretary Kerry and his team, including General [John] Allen, have been working day and night to try to promote a secure peace for Israel because of the Secretary’s deep concern for Israel’s future,” she added. “To question his motives and distort his proposals is not something we would expect from the defense minister of a close ally.”

The American rebukes came several hours after a gentler reprimand of Ya’alon from Netanyahu, in a speech before the Knesset marking the Israeli parliament’s 65th birthday.

“Even when we have disagreements with the United States, they are always substantive and not ad hominem,” Netanyahu said.

“We are working to advance regional security and defend our interests. True peace is founded on recognition of the nation-state of the Jewish people and on security arrangements guaranteeing that territories in Palestinian hands do not turn into launching pads for terrorists,” Netanyahu said, adding, “but all that [must be achieved] while respecting our important ties to the United States. We continue to defend our national interests, one of which is the continued fostering of our relations with our ally, the United States.”

Senior Obama administration officials were not satisfied with Netanyahu’s comments, and reportedly asked the prime minister to explicitly affirm his government’s commitment to the US-led peace talks with the Palestinian, and distance himself from Ya’alon’s comments.

Ya’alon was also assailed for his reported comments by President Shimon Peres and several senior cabinet colleagues, including from the right.

In his own speech before the Knesset Tuesday, Peres praised Kerry and US President Barack Obama’s efforts to achieve peace with the Palestinians.

“We are grateful to the president of the United States, Barack Obama, for his unreserved responsiveness to [Israel’s] security and intelligence needs. There is no doubt he wants to see a Middle East at peace. The deep friendship with the United States is a central element of Israel’s security and a catalyst for peace in the Middle East. Secretary of State John Kerry’s determined efforts to achieve peace are evidence of this American stance,” Peres said.

In a statement from Geneva, where he is meeting with UN High Commissioner for Human Rights Navi Pillay, Foreign Minister Avigdor Liberman chastised the “loud, public argument” with the US that Ya’alon had sparked.

“Minister Liberman said that Israel and the US have a special relationship, and the US is Israel’s most steadfast ally over the years, which it has proven many times,” Liberman’s spokesman Tzahi Moshe said in a statement. “Therefore, it is inappropriate and unhelpful to both sides to conduct a loud, public argument, and there is no call for personal attacks, even if there are, at times, disagreements.”

Ya’alon, considered a defense hawk, has publicly expressed skepticism over plans for Israel to pull out of the West Bank, and firmly opposed an Israeli withdrawal from the Jordan Valley.

Ya’alon has been a strident critic of the American-brokered peace talks, which began in July and stipulated a nine-month window, until April, to reach a final status agreement.

Kerry has made 10 visits to the region this year, shuttling between Israeli and Palestinian leaders to mediate talks. Recently, he has been pushing a framework agreement as part of his efforts to nudge Abbas and Netanyahu closer to a full treaty that would establish a Palestinian state alongside Israel. But the two sides have reportedly been at odds over almost every aspect of the core issues involved in a two-state accord.

Haviv Rettig Gur and Gavriel Fiske contributed to this report