KYIV, Ukraine >> Secretary of State Antony Blinken traveled to Ukraine’s capital today and met with President Volodymyr Zelenskyy, delivering a U.S. vote of confidence — and the promise of more aid — even as Russia made one of the deadliest attacks of the war on civilians.

A Russian missile struck Kostyantynivka, an eastern city near the front lines, killing at least 17 people and wounding at least 32 others, and more might still be trapped in the rubble, according to Ukrainian officials. They said the attack hit an outdoor marketplace about 2 p.m., when it was busy with vendors and shoppers, while Blinken was in Kyiv.

“A regular market. Shops. A pharmacy. People who did nothing wrong. Many wounded. Unfortunately, the number of casualties and the injured may rise,” Zelenskyy wrote on Telegram. For anyone around the world to continue to deal with Russia, he added, “means turning a blind eye” to atrocities.

Early in the morning, Russia launched a volley of missiles and drones, several of them at Kyiv, hours before Blinken arrived, the Ukrainian military said, including a drone that killed at least one person in Izmail, a small port city on the Danube River in southern Ukraine.

Blinken’s trip, which was not announced in advance for security reasons, came as Zelenskyy’s government wages an increasingly public fight against the official corruption that has long been endemic in his country.

Some lawmakers in the United States and Europe have cited that problem — as well as the grueling pace of Kyiv’s counteroffensive to retake Russian-occupied territory — in voicing doubts about continuing to spend billions to arm and support Ukraine. That has put pressure on Zelenskyy and the Biden administration to show progress against graft.

“We’re engaged in assisting the government of Ukraine on anti-corruption efforts and on efforts to ensure accountability and full transparency of all the assistance we’re providing, as well as the security of U.S.-provided defense articles and technologies,” Blinken said at a news conference after his meeting with Zelenskyy, who did not take part in the news conference.

“President Zelenskyy and I discussed these issues today, and the importance to Ukraine’s democratic future of continued reforms and the fight against corruption,” he said.

After a series of military procurement and enlistment scandals, this week Zelenskyy dismissed his defense minister, Oleksii Reznikov, the biggest shake-up in his administration during a year and a half of war. The Ukrainian parliament today confirmed the appointment of his successor, Rustem Umerov.

Blinken, making his fourth trip to Kyiv since the invasion, stated repeatedly that American backing was unshaken. “Ukraine’s security is integral to the security of the entire Euro-Atlantic community and indeed it’s integral to security around the world, because of the principles that are being challenged here,” he said at the news conference with Ukrainian Foreign Minister Dmytro Kuleba.

He announced more than $1 billion in new aid, including $665.5 million in military and other security assistance, drawing on spending authority already granted by Congress to the Biden administration. He noted that much of the aid was intended not for the current fight but for long-term security and rebuilding Ukrainian society.

“For the first time we are transferring to Ukraine assets seized from sanctioned Russian oligarchs, which will now be used to support Ukrainian military veterans,” he said. “Those who have enabled Putin’s war of aggression should pay for it.”

In all, the United States has supplied $43 billion in equipment, including weaponry, training and other military and law enforcement aid, since Russia’s full-scale invasion began in February 2022, and more than $20 billion in economic and humanitarian aid. President Joe Biden has asked Congress to authorize an additional $24 billion.

The Defense Department said today that the administration plans to send ammunition made with depleted uranium to Ukraine — the latest in a series of escalations in what kinds of weaponry the United States supplies to Kyiv. The British government said in March that it would give Ukraine depleted uranium munitions.

Rounds made with uranium, used for decades by the United States and other countries, are more effective at penetrating armor than those made with other metals, and more likely to ignite fires. Some U.S. tanks have armor that incorporates depleted uranium.

The metal, a byproduct of making fuel for nuclear reactors, is mildly radioactive. Some advocates have expressed concerns that prolonged exposure could cause illness, or that spent ammunition could cause environmental contamination, but the Pentagon has said those fears are unfounded.

The Biden administration has repeatedly resisted and then relented on sending weapons systems to Ukraine — HIMARS rocket artillery, Patriot air defense missiles, Abrams tank, F-16 fighter jets and cluster munitions, among others.

Blinken said he and Zelenskyy had discussed ideas for a long-term security partnership that the Ukrainian leader has said should resemble the U.S. alliance with Israel. Such an arrangement, which 28 other countries have also expressed interest in having with Ukraine, would provide it with some assurances short of joining the NATO alliance, which some member countries consider a far-off goal.

This article originally appeared in The New York Times.