Russia-Ukraine updates: Putin suspends key US-Russia nuclear treaty in speech denouncing West

U.S. Secretary of State Antony Blinken met with Ukrainian President Volodymyr Zelenskyy at the heavily fortified Presidential Administration Building in Kyiv.

The meeting took place in a gilded room darkened by blackout shades. Other windows in the building were covered by sandbags.

Blinken was joined by his deputy chief of staff, Thomas Sullivan; Under Secretary of State for Political Affairs Victoria Nuland; U.S. Ambassador to Ukraine Bridget Brink; and Assistant Secretary of State for European and Eurasian Affairs Karen Donfried. Zelenskyy was accompanied by his foreign minister, Dmytro Kuleba, Ukraine’s ambassador to the U.S., Oksana Marakova, and other top members of his cabinet.

In English, Zelenskyy thanked the U.S. for its "enormous" support, saying he appreciated the delegation’s visit. He also presented Blinken with a Ukrainian medal, "The Order of Prince Yaroslav the Wise," awarded for distinguished service to the country.

Blinken commended the bravery of the Ukrainian people and their success on the battlefield, noting the counteroffensive underway was proving "incredibly effective," calling it a "pivotal moment" that would put Kyiv on better footing for future negotiations.

“This is your homeland, not Russia’s,” he said. “It’s as basic as that.”

Blinken also spoke about the recent announcement of $2 billion in long-term aid for Ukraine and other countries in the region deemed to be at risk of facing Russian aggression, highlighting the “durable and enduring” commitment of the United States.

He noted how Russia was feeling the impact of economic sanctions, pointing to Moscow turning to Iran and North Korea for weapons as evidence.

Blinken last met with Zelenskyy in person in April, when he visited Kyiv.

-ABC News' Shannon Crawford

U.S. Secretary of State Antony Blinken met with his Ukrainian counterpart, Dmytro Kuleba, spending about 45 minutes inside Ukraine’s Ministry of Foreign Affairs Thursday.

Prior to that, Blinken visited a children’s hospital in Kyiv where he met Patron, a bomb-sniffing Jack Russell terrier. The secretary presented Patron with treats and held him as they posed for a photo.

He also distributed stuffed animals to young patients present, including a 6-year-old girl, Maryna, who lost her leg and is learning to walk with a prosthetic.

This latest unannounced visit to Ukraine is the secretary’s fifth trip to the country and his third since the outbreak of the war. Blinken last visited Kyiv in late April. Blinken and Secretary of Defense Lloyd Austin remain the highest-level American officials to visit the country in the wake of Russia’s invasion.

-ABC News' Shannon Crawford

U.S. Secretary of State Antony Blinken arrived in Kyiv on Thursday for an unannounced visit to war-torn Ukraine.

His visit came on the heels of U.S. Secretary of Defense Lloyd Austin's announcement of a $675-million package of heavy weaponry, ammunition and armored vehicles for Ukraine amid Russia's ongoing invasion. In addition, Blinken announced Thursday that the Biden administration would provide a further $2 billion in long-term foreign military financing to Ukraine and 18 of its neighbors, including NATO members and regional security partners "most potentially at risk for future Russian aggression."

The United States will send another $675 million in assistance to Ukraine amid Russia's war, Secretary of Defense Lloyd Austin announced Thursday.

"Yesterday, President Biden approved the latest tranche of U.S. assistance to Ukraine, valued at up to $675 million, and this is the Biden administration's 20th drawdown of equipment from U.S. stocks for Ukraine since last August," Austin told reporters at the U.S. military's Ramstein Air Base in Germany, where he attended a meeting of the Ukraine Defense Contact Group.

"The latest package includes more GMLRS, 105 millimeter howitzers, artillery ammunition and HARMs, Humvees, armored ambulances, anti-tank systems, small arms and more," he added.

The Ukraine Defence Contact Group is a U.S.-led effort to bring together defense leaders from dozens of countries around the world in order to facilitate military support for Ukraine in its ongoing efforts to fight the Russian invasion. Austin said Thursday that the group was meeting to "renew our commitment and intensify our momentum to support the brave defenders of Ukraine for the long term."

"Today, four months after our initial Contact Group meeting, the war is at another key moment. Russian forces continue to cruelly bombard Ukrainian cities and civilians with missiles and artillery fire," he said. "But Ukrainian forces have begun their counteroffensive in the south of their country."

"This Contact Group needs to position itself to sustain Ukraine's brave defenders for the long haul," he added. "And that means a continued and determined flow of capability now."