Hours after North Korea tested new nuclear technology, Donald Trump’s campaign chief refused Friday to outline the Republican presidential nominee’s approach to rising tensions on the Korean Peninsula as both White House contenders increasingly focus on national security.

Trump campaign manager Kellyanne Conway, pressed repeatedly on Trump’s plan, said only, “He wouldn’t do what’s being done now.”

“He’s not going to reveal all of his plans, and he’s made that very clear. And maybe someone can ask him in a debate,” Conway told CBS “This Morning.” “But the fact is that this entire world would be put on notice that there’s a strong leader in the White House.”

Democrat Hillary Clinton’s running mate, Virginia Sen. Tim Kaine, said Clinton would rely on sanctions and pressure from other nations to help control North Korea. The rogue nation said Friday that it conducted a “higher level” nuclear test explosion that will allow it to finally build an array of stronger, smaller and lighter nuclear weapons.

“Hillary Clinton is going to use that sanctions power to the utmost to really squeeze those who are supplying North Korea,” Kaine told CBS, suggesting that nations such as China must play a critical role in pressuring North Korea to back off.

“I think this is a wake-up call for them,” Kaine said of China. “We have to demand they use their influence.”

North Korea’s latest test was its fifth atomic test, and the second in eight months. South Korean President Park Geun-hye said the detonation, which Seoul estimated was the North’s biggest-ever in explosive yield, was an act of “fanatic recklessness” and a sign that leader Kim Jong Un “is spiraling out of control.”

President Barack Obama condemned the test and said the U.S. would never accept the country as a nuclear power.

The development comes at the end of a week in which Trump and Clinton clashed repeatedly over national security.

The New York billionaire attacked Clinton’s record as the nation’s chief diplomat, yet he faced criticism from within his own party for refusing to outline his plans for combating foreign policy challenges, including threats posed by the Islamic State group. Trump said this week that he does indeed have a plan, but would convene military leaders in his first 30 days in office to craft another plan.

Trump has also faced criticism for praising Russian President Vladimir Putin during a high-profile national security forum earlier in the week. The Republican nominee also granted an interview to a Russian-backed television network on Thursday.

With several prominent Republican national security officials already concerned about Trump’s national security acumen, Clinton has tried to cast herself as the better commander in chief.

The former secretary of state plans to meet with foreign policy and national security experts in New York City Friday afternoon to discuss ways to combat terrorism.

Attendees include officials who have served in Democratic and Republican administrations, such as retired Marine General John Allen, former CIA director David Petraeus and Michael Chertoff and Janet Napolitano, both former Secretaries of Homeland Security.

Clinton has aggressively promoted her growing list of military endorsements from both parties.

On Friday, her campaign said the number of retired generals and admirals endorsing Clinton for president has grown to 110. Clinton stressed that she has more military backing than Trump, who touted endorsements from 88 retired U.S. generals and admirals earlier in the week.

Dozens of Republican national security officials released a letter last month warning that Trump would be “the most reckless president in American history.”

Trump was set to appear at a Friday night rally in Pensacola, Florida, the latest in a handful of military-rich communities the Republican has targeted this week. He’ll also address religious activists at a conference for social conservatives Friday afternoon in Washington.

Clinton, continuing her aggressive fundraising push, is also appearing at two fundraisers in New York City Friday. One of them is an LGBT event featuring Barbra Streisand.

Clinton is getting some help from another wealthy backer as well.

Billionaire Facebook co-founder Dustin Moskovitz on Friday said he’s giving $20 million to help defeat Trump. He called the Republican presidential candidate divisive and dangerous and his appeals to Americans who feel left behind “quite possibly a deliberate con.”

Moskovitz said Democrats and their nominee, Hillary Clinton, are “running on a vision of optimism, pragmatism, inclusiveness and mutual benefit.”