(Recasts with joint patrol by Russian, Chinese jets, Japan's response)
By Trevor Hunnicutt and Kiyoshi Takenaka
TOKYO, May 24 (Reuters) - Japan scrambled jets after Russian and Chinese warplanes neared its airspace during a visit by U.S. President Joe Biden on Tuesday, with Tokyo conveying "grave concerns" about what it saw as a provocative move timed to coincide with the Quad summit.
The issues of Taiwan and Russia loomed over the meeting in Tokyo of leaders of the Quad grouping of the United States, Japan, Australia and India, who stressed their determination to ensure a free and open Indo-Pacific region in the face of an increasingly assertive China.
Japanese Prime Minister Fumio Kishida said the group was not aimed at any one country.
As the leaders met, Russian and Chinese warplanes conducted a joint patrol that lasted 13 hours in the region, in what Japanese Defence Minister Nobuo Kishi characterised as a likely provocation by both Beijing and Moscow.
The patrol took place after President Joe Biden angered China by saying a day earlier he would be willing to use force to defend the democratic island of Taiwan. On Tuesday, he said there was no change to a U.S. policy of "strategic ambiguity" on Taiwan.
"We believe the fact that this action was taken during the Quad summit makes it more provocative than in the past," Kishi said of the Chinese and Russian exercises.
Japan scrambled jets and conveyed "grave concerns" to Russia and China through diplomatic channels, Kishi said at a news conference after Biden had departed Tokyo.
South Korea's military also scrambled fighters, saying at least four Chinese and four Russian warplanes entered its air defence zone.
The patrols, the first since Russia's invasion of Ukraine, were part of an annual military exercise, China's defence ministry said on its website. The two countries have conducted the exercises since 2019, but in the latter half of the year.
The leaders of the Quad grouping said in a joint statement issued after their talks that they "discussed their respective responses to the conflict in Ukraine and the ongoing tragic humanitarian crisis".
QUAD CONCESSION TO INDIA?
In an apparent concession to India, which has long had close ties with Russia, the words "Russia" or "Russian" did not appear in the statement.
Following the Quad summit, Kishida said the leaders, including Prime Minister Narendra Modi of India, had shared their concerns about Ukraine and all four agreed on the importance of the rule of law, sovereignty and territorial integrity.
Biden's comment on Taiwan, which was not even on the official agenda at the Quad meeting, was the focus of much of the attention of the delegations and media.
While Washington is required by law to provide self-ruled Taiwan with the means to defend itself, it has long followed the policy of "strategic ambiguity" on whether it would intervene militarily to protect it in the event of a Chinese attack - a convention Biden appeared to break on Monday.
On Tuesday, Biden, asked if there had been any change to the U.S. policy on Taiwan, responded: "No."
"The policy has not changed at all. I stated that when I made my statement yesterday," he said after the talks with his Quad counterparts.
China considers Taiwan an inalienable part of its territory and says it is the most sensitive and important issue in its relationship with Washington.
Biden's comment on Monday, when he volunteered U.S. military support for Taiwan, was the latest in a series of apparently off-the-cuff assertions that suggest his personal inclination is to defend the island.
Some critics have said he has mis-spoken on the issue, or made a gaffe, but other analysts have suggested that given Biden's extensive foreign policy experience and the context in which he made the remarks, next to Kishida and after the Russian invasion of Ukraine, he had not spoken in error.
Other analysts and advisers said Biden would be carrying a clear message to China during his trip - don't try what Russia did in Ukraine anywhere in Asia, especially not Taiwan.
A Chinese foreign ministry spokesman said on Tuesday that the one-China principle could not be shaken and that no force in the world, including the United States, could stop China from achieving "complete reunification".
Biden left Tokyo shortly after sunset on his way back home.
Speaking to reporters, Biden condemned Russia's invasion of Ukraine, saying it had global ramifications.
"Russia's assault of Ukraine only heightens the importance of those goals of fundamental principles of international order, territorial integrity and sovereignty. International law, human rights must always be defended regardless of where they're violated in the world," he said.
Kishida echoed Biden's condemnation of Russia, saying its invasion "shakes the foundation of international order" and was a direct challenge to the principles of the United Nations.
"We should not allow similar things to happen in the Indo-Pacific region," he said.
Biden said the United States would stand with its "close democratic partners" to push for a free and open Indo-Pacific.
The United States has been frustrated with what it regards as India's lack of support for U.S.-led sanctions on Russia and condemnation of the invasion. India has also abstained in U.N. Security Council votes on Russia's invasion.
New Australian Prime Minister Anthony Albanese said that "strong views" were expressed in the talks about Russia but did not give details.
Albanese told his fellow leaders he wanted them all to lead on climate change.
"The region is looking to us to work with them and to lead by example," he said.
China has been extending its influence in the Pacific where island nations face some of the most direct risks from rising seas. Top Chinese diplomat Wang Yi will in coming days visit the Solomon Islands, which recently signed a security pact with China despite U.S and Australian misgivings.
(Reporting by Trevor Hunnicutt, Sakura Murakami, David Dolan, Chang-Ran Kim, Kiyoshi Takenaka, Ju-min Park, Nobuhiro Kubo, Krishna Das and Martin Pollard; Writing by Trevor Hunnicutt and Elaine Lies; Editing by Michael Perry, Robert Birsel, Edmund Klamann and Raju Gopalakrishnan)