WASHINGTON, Sept 24 (Reuters) - Leaders of the United States, Japan, India and Australia presented a united front on Friday at their first summit and stressed the need for a free and open Indo-Pacific region amid shared concerns about China. The two-hour meeting at the White House of the Quad, as the grouping of the four major democracies is called, will be watched closely in Beijing, which criticized the group as "doomed to fail." The summit was expected to yield progress on COVID-19 vaccines, infrastructure and technological cooperation. While China was not mentioned in the public remarks by the four leaders, Beijing was clearly top of mind. "We stand here together, in the Indo-Pacific region, a region that we wish to be always free from coercion, where the sovereign rights of all nations are respected and where disputes are settled peacefully and accordance with international law," Australian Prime Minister Scott Morrison told the start of the meeting. U.S. President Joe Biden met first with Indian Prime Minister Narendra Modi in the Oval Office, and then told his Quad partners that a vaccine initiative agreed at a virtual Quad summit in March was "on track to produce an additional 1 billion doses of vaccine in India to boost total supply." Modi said the initiative would be a great help for countries in the Indo-Pacific region. The plan to supply a billion COVID-19 shots across Asia by the end of 2022 stalled after India, the world"s largest vaccine producer, banned exports in April amid a massive COVID outbreak at home. India has said it is ready to restart vaccine exports in the October quarter, prioritizing the COVAX international vaccine initiative and neighboring countries. Neither Biden nor the other leaders responded when asked when vaccine deliveries would start under the Quad initiative. The Quad is expected to announce several new agreements, including one to bolster supply chain security for semiconductors and to combat illegal fishing and boost maritime domain awareness, a senior U.S. official said, referring to initiatives prompted by concerns about China. The group will also roll out a 5G partnership and plans for monitoring climate change. Biden said the Quad represented four "democratic partners who share a world view and have a common vision for the future." Japanese Prime Minister Yoshihide Suga said the meeting showed strong solidarity between countries and their "unwavering commitment to a ... free and open Indo-Pacific." The meeting came just over a week after the United States, Britain and Australia announced an AUKUS security pact under which Australia will be provided with nuclear-powered submarines, a move that has been roundly denounced by Beijing. Chinese Foreign Ministry spokesman Zhao Lijian appeared to criticize the Quad in a briefing on Friday. "A closed, exclusive clique targeting other countries runs counter to the trend of the times and the aspirations of regional countries. It will find no support and is doomed to fail," he said. Before the meeting, U.S. officials sought to play down the security aspect of the Quad - even though its members carry out naval exercises together and share concerns about China"s growing power and attempts to exert pressure on all four countries. China has denounced the Quad as a Cold War construct and says the AUKUS alliance would intensify an arms race in the region. Vice President Kamala Harris had a joint meeting with Suga and Morrison after the Quad talks ended, as Modi departed Washington to return to New York for U.N. meetings. Suga, who is stepping down as Japan"s leader, was also holding a separate meeting with Biden after the Quad session. Suga wanted to discuss with Biden China"s recent efforts to join the CPTPP Pacific trade pact, the U.S. official said.