The U.S. government has offered and is prepared to help Ukrainian President Volodymyr Zelensky leave the capital city of Kyiv to avoid being captured or killed by advancing Russian forces, according to U.S. and Ukrainian officials. But so far, the president has refused to leave.

As Russian forces ratcheted up their attacks on Friday, a defiant Zelensky pledged to remain in place. “Acording to the information we have, the enemy has marked me as target No. 1, my family as target No. 2,” he told Ukrainians in an early-morning address. “They want to destroy Ukraine politically by destroying the head of state.”

Ukrainian President Volodymyr Zelenskyy speaks at a joint news conference Wednesday with Polish President Andrzej Duda and Lithuania’s President Gitanas Nauseda after their talks in Kyiv. Associated Press/Efrem Lukatsky

U.S. officials have spoken to Zelensky about a range of security issues, including the safest places for the president to situate himself in the hopes of ensuring continuity of government as Ukraine fends of a Russian invasion, said a senior U.S. official, who was not authorized to speak publicly.

“We have been making him aware not only of the threat of Russian invasion, now a reality, but also the threat to him personally,” said Rep. Adam Schiff, D-Calif., the chairman of the House Intelligence Committee.

“We stand ready to assist him in any way,” Schiff said.

Perhaps the swiftest way for Russia to end the war in Ukraine, several current and former national security officials said, would be to kill Zelensky or capture him. Russian President Vladimir Putin might avoid a costly, protracted occupation of Ukraine by forcing Zelensky out and installing a compliant leader in his place.

Zelensky has known for weeks about U.S. concerns for his safety.

When CIA Director William J. Burns flew to Ukraine in January to meet with the Ukrainian president about the growing Russian threat to his country, Zelensky asked whether he or his family were personally in danger, according to an aide, who said that the leader was skeptical the Russians would try to kill him.

Burns didn’t share any specific information but made clear that Zelensky needed to take his personal security seriously, the aide said.

At the time, intelligence suggested that Russian hit teams might already have infiltrated Kyiv, weeks before the first Russian forces ever crossed the border, according to officials familiar with the information.

Zelensky publicly downplayed the threat of a Russian invasion. He and his aides acknowledged that Putin might order the forces massing in huge numbers on Ukraine’s borders to strike, but they said U.S. and other European leaders also risked igniting a public panic and economic catastrophe with their constant warnings of an imminent attack.

Now that Russia has attacked, U.S. officials warned this week that Putin’s goal was to decapitate the Ukrainian government. White House Press Secretary Jen Psaki indicated to reporters on Thursday that the U.S. had plans to assist Zelensky if he were personally threatened.

“We’re not going to get into security – security questions, but we are in touch with President Zelensky, and we are working to provide him a range of support,” Psaki said.

So far, Zelensky hasn’t taken Washington up on its offer. And according to a Ukrainian official, Zelensky has not directed his own security services to remove him to a safe city, such as Lviv, although they stand ready to do so.

Fending off rumors that he had fled, Zelensky posted a video on Telegram on Friday surrounded by his top advisers and prime minister in front of Bankova, Ukraine’s equivalent to the White House.

“We are all here. Defending our independence. Our country. And so it will continue,” Zelensky said.

Zelensky noted in his earlier remarks that his family remained in Ukraine, as well, but he declined to say where.

Some officials praised the Ukrainian leader for staying in place despite the risk to himself and his government and the warnings he has received.

“The U.S. has been very forward-leaning both in sharing threat information with the government of Ukraine, including President Zelensky, as well as declassifying a significant amount of intelligence to ensure that the world knew about Russia’s plans for this unprovoked aggression,” said Sen. Mark Warner, D-Va., the chair of the Senate Intelligence Commitee. “President Zelensky has courageously decided to stay and lead from Kyiv.”

In his address, Zelenksy said that “sabotage groups” had infiltrated Kyiv. Later, his government released an update warning that “enemy reconnaissance and sabotage groups operate insidiously, disguising themselves in civilian clothes and infiltrating cities in order to destabilize the situation by carrying out sabotage operations.”