"On my way to the US to strengthen resilience and defence capabilities of Ukraine," Zelenskyy said in a tweet.
ADVERTISEMENTUkrainian President Volodymyr Zelenskyy is preparing to visit Washington DC on Wednesday in his first known trip outside the country since Russia's full-scale invasion in late February.
The Ukrainian leader confirmed he was "on his way" to the US capital in a tweet.
"On my way to the US to strengthen resilience and defence capabilities of Ukraine," Zelenskyy said.
"In particular, (US President Joe Biden) and I will discuss cooperation between Ukraine and the US. I will also have a speech at the Congress and a number of bilateral meetings."
Zelenskyy's visit could still be called off at the last minute due to security concerns, congressional sources told AP.
The visit to Washington is set to include an address to Congress on Capitol Hill and a meeting with President Joe Biden.
It comes as lawmakers are set to vote on a year-end spending package that includes about $45 billion (€42.4bn) in emergency assistance to Ukraine and as the US prepares to send Patriot surface-to-air missiles to the country to help stave off Russia's invasion.
The trip comes a day after Zelenskyy made a daring and dangerous trip to what he called the hottest spot on the 1,300-kilometre front line, the city of Bakhmut in Ukraine's contested Donetsk province, where he praised Ukrainian troops for their "courage, resilience and strength" as artillery boomed in the background.
The Ukrainian leader told the troops he passed through Sloviansk, Kramatorsk and Druzhkivka to reach Bakhmut in an unannounced trip that appeared designed to show Moscow's failure to capture the city and dishearten the Russians trying to surround it.
"Bakhmut Fortress. Our people. Unconquered by the enemy. Who with their bravery prove that we will endure and will not give up what's ours," he wrote on his Telegram channel, thanking the troops for "the courage, resilience and strength shown in repelling the enemy attacks.
"Since May, the occupiers have been trying to break our Bakhmut, but time goes by and Bakhmut is already breaking not only the Russian army, but also the Russian mercenaries who came to replace the wasted army of the occupiers," he said.
Washington to deliver Patriot systems
Russia's invasion, which began on 24 February, has lost momentum in recent weeks. The illegally annexed provinces of Donetsk, Kherson, Luhansk and Zaporizhzhia remain fiercely contested.
Capturing Bakhmut would sever Ukraine's supply lines and open a route for Russian forces to press on toward cities that are key Ukrainian strongholds in the Donetsk province.
In a video released by his office from the Bakhmut visit, Zelenskyy was handed a Ukrainian flag and alluded to delivering it to US leaders.
"The guys handed over our beautiful Ukrainian flag with their signatures for us to pass on," Zelenskyy said in the video.
"We are not in an easy situation. The enemy is increasing its army. Our people are braver and need more powerful weapons. We will pass it on from the boys to the Congress, to the president of the United States. We are grateful for their support, but it is not enough. It is a hint — it is not enough."
The latest tranche of US funding would be the biggest American infusion of assistance yet to Ukraine and ensure that funding flows to the war effort for months to come.
On Wednesday, the US was also set to announce that it will send $1.8bn (€1.69bn) in military aid to Ukraine in a major package that will, for the first time, include a Patriot missile battery and precision-guided bombs for its fighter jets, US officials said.
ADVERTISEMENTThe aid signals an expansion by Washington in the kinds of advanced weaponry it will send to Ukraine to bolster its air defences against what has been an increasing barrage of Russian missiles in recent weeks.
The decision to send the Patriot battery comes despite threats from Russia's Foreign Ministry that the delivery of the advanced surface-to-air missile system would be considered a provocative step and that the Patriot and any crews accompanying it would be a legitimate target for Moscow's military.
It's not clear exactly when the Patriot would arrive on the front lines in Ukraine since US troops will have to train Ukrainian forces on how to use the high-tech system.
The training could take several weeks, and is expected to be done in Germany. To date, all training of Ukraine's forces by the US and its Western allies has taken place in European countries.
Also included in the package will be an undisclosed number of Joint Direct Attack Munitions kits, or JDAMs. The kits will be used to modify massive bombs by adding tail fins and precision navigation systems so that rather than being simply dropped from a fighter jet onto a target, they can be released and guided to a target.
ADVERTISEMENTPutin brags about 'courage' of Moscow forces
For his part, Russian President Vladimir Putin on Tuesday hailed the "courage and self-denial" of his forces in Ukraine — but he did so at a ceremony in an opulent and glittering hall at the Kremlin in Moscow, not on the battlefield.
Mercenaries from the Wagner Group, a shadowy Russian military contractor, are reported to be leading the charge in Bakhmut.
Unverified videos on a popular Russian social media platform showed the Wagner Group's leader, Yevgeny Prigozhin, standing near an artillery piece and saying he was ready to meet Zelenskyy in Bakhmut.
At the Kremlin ceremony, Putin presented awards to the Moscow-appointed heads of the four illegally annexed regions of Ukraine.
"Our country has often faced challenges and defended its sovereignty," Putin said. "Now Russia is again facing such a challenge. Soldiers, officers and volunteers are showing outstanding examples of courage and self-denial on the front line."
ADVERTISEMENTIn a video address honouring Russia's military and security agencies, he praised the security personnel deployed to the four regions, saying that "people living there, Russian citizens, count on being protected by you."
Putin acknowledged the challenges faced by the security personnel.
"Yes, it's difficult for you," he said, adding that the situation in the regions is "extremely difficult."
British authorities, meanwhile, gave a bleak assessment of how the war was going for the Kremlin.
Some 100,000 Russian troops were "dead, injured or have deserted" in the invasion, UK Defence Secretary Ben Wallace said.
ADVERTISEMENTWallace did not give a figure for Ukrainian casualties, but the US military recently put the estimated number of Ukrainian troops killed and wounded at about 100,000.
Losses in Russia's military command have also taken a toll, as has the destruction of equipment. "Not one single operational commander then in place on 24 February is in charge now," Wallace told lawmakers in the House of Commons. "Russia has lost significant numbers of generals and commanding officers."
"Russian capability has been severely hampered by the destruction of more than 4,500 armoured and protected vehicles, as well as more than 140 helicopters and fixed wing aircraft," Wallace said.
Ukraine's counteroffensive has succeeded in recapturing large swaths of land. After 300 days of war, the UK Ministry of Defence tweeted, Ukraine has liberated about 54% of the maximum amount of extra territory Russia seized in the invasion. It didn't say what portion of Ukrainian territory Russia controlled at the peak of its gains.
Russia now controls about 18% of internationally recognised areas of Ukraine, including those parts of the eastern Donbas and the Crimean Peninsula seized in 2014.
ADVERTISEMENTWith the fighting in the east at a stalemate, Moscow has used missiles and drones to attack Ukraine's power equipment, hoping to leave people without electricity as freezing weather sets in.
Life in the Ukrainian capital took a minor but welcomed step toward normality with the reopening of two of Kyiv's main subway stations for the first time since the war began.
The key hubs of Maidan Nezalezhnosti and Khreschatyk, like the capital's other underground stations, have served as air raid shelters.
"It's the feeling that despite everything, we are returning to a routine that we were used to," said 24-year-old passenger Denys Kapustin. "This is very important."