Originally Published: 20 MAR 23 23:14 ET

Updated: 21 MAR 23 10:21 ET

By Jessie Yeung and Teele Rebane, CNN

(CNN) -- Japanese Prime Minister Fumio Kishida has made a surprise trip to Ukraine to meet Ukrainian President Volodymyr Zelensky -- a day after Chinese leader Xi Jinping met his Russian counterpart Vladimir Putin in Moscow.

Kishida arrived in Kyiv on Tuesday afternoon local time, and also traveled to Bucha, the town just north of the Ukrainian capital that has become synonymous with Russian atrocities and alleged war crimes.

Emine Dzheppa, First Deputy Minister of Foreign Affairs of Ukraine, said the country "is happy to welcome" the Japanese premier.

"This historic visit is a sign of solidarity and strong cooperation between Ukraine and Japan," she tweeted Tuesday alongside pictures of Kishida's arrival.

"We are grateful to Japan for its strong support and contribution to our future victory," added Dzheppa.

Kishida's trip is the first time a Japanese prime minister has visited a country or region with ongoing fighting since World War II, NHK reported. It will also be the first visit to Ukraine by an Asian member of the G7 grouping and the first by a US ally in the region.

The dual visits by Kishida and Xi underscore deep divisions in northeast Asia toward the war in Ukraine, with Japan pledging substantial aid for Kyiv, while China remains a lone voice supporting an increasingly isolated Putin -- now a global pariah and suspected war criminal.

In the face of China's growing assertiveness and global reach, Japan and the United States have moved closer in recent years, especially on regional security and intelligence cooperation.

Japan is also a member of the Quad, the informal group focused on security that includes India, Australia and the United States.

In a statement released Tuesday, Japan's Ministry of Foreign Affairs said Kishida's visit to Ukraine was at Zelensky's invitation, and that Kishida would return to Japan on Thursday.

During the visit, Kishida will "directly convey our solidarity and unwavering support for Ukraine" and "resolutely reject Russia's aggression against Ukraine," said the statement.

Kishida has previously spoken out forcefully against Moscow's invasion of its neighbor, warning last year that "Ukraine today may be East Asia tomorrow."

Last month, on the eve of the invasion's one-year anniversary, Japan pledged $5.5 billion in humanitarian aid to Ukraine, quadrupling Tokyo's previous contributions.

"Russia's aggression against Ukraine is not just a European matter, but a challenge to the rules and principles of the entire international community," Kishida said at the time.

And during his visit to New Delhi on Monday, Kishida announced a new plan to invest $75 billion in the Indo-Pacific, according to Reuters -- widely seen as a bid to deepen ties with countries in South and Southeast Asia and to counter China's influence.

Xi meets 'dear friend' Putin

The Japanese leader's visit to Ukraine follows Xi's controversial state visit to Russia, his first since the invasion began, with the first day of talks starting on Monday.

Xi's visit has been framed by Beijing as a peacemaking project -- despite deep skepticism in Kyiv and the West.

For the US and much of Europe, the Chinese leader's presence in Moscow is seen as a ringing endorsement for Putin at a time when his military is running out of supplies and Russia's economy is struggling under Western sanctions.

Throughout the invasion, China has backed Kremlin rhetoric blaming NATO for the conflict, refused to condemn the invasion, and continued to support Moscow financially by significantly increasing purchases of Russian fuel.

India is the only other Asian nation that has taken a similar stance, refusing to formally condemn Russia's invasion and continuing to purchase of Russian oil.

Modi told Putin last September that it was not the time for war, in an apparent criticism -- although India has continued to maintain pivotal ties with Moscow.

During his visit on Monday, Xi praised Putin and called him a "dear friend." They discussed the Ukraine war, with further meetings scheduled on Tuesday.

The Wall Street Journal reported last week that Xi planned to speak with Zelensky after his trip to Moscow, citing "people familiar with the matter."

It would be the first time the two leaders have spoken since Russia launched its invasion.

Ukrainian, Chinese and US officials all declined to confirm the potential virtual meeting.