NEW DELHI—Top diplomats from the U.S. and India said the two countries were committed to resolving the conflict in Afghanistan, while acknowledging the Taliban has made new territorial gains, sparking fears in New Delhi about an increase in terrorism.

Secretary of State Antony Blinken’s visit to India was partly aimed at reassuring an important Asian partner as the U.S. withdraws troops from Afghanistan. Speaking with his Indian counterpart Wednesday, Mr. Blinken said the U.S. maintained its diplomatic and economic commitment to the country.

In recent weeks, the Taliban has occupied critical border junctions with Pakistan and 212 districts—mainly rural, northern areas—out of 426 in the country, according to Indian officials. India and other countries in the region fear the territorial gains by the Taliban, which has had the backing of Pakistan, could make Afghanistan a breeding ground for terrorist activities.

India’s Minister of External Affairs Subrahmanyam Jaishankar greeted Secretary of State Antony Blinken on Wednesday in New Delhi.

India’s Minister of External Affairs Subrahmanyam Jaishankar greeted Secretary of State Antony Blinken on Wednesday in New Delhi.

Photo: Jonathan Ernst/Associated Press

India’s Minister of External Affairs Subrahmanyam Jaishankar said on Wednesday that the consequences of the U.S. military withdrawal were inevitable. “What is done is done,” he said. “It is a policy taken, and I think in diplomacy you deal with what you have.”

Mr. Jaishankar said there is broad consensus that the conflict requires a diplomatic rather than a military resolution.

Mr. Blinken said the Taliban is alleged to have committed new atrocities, without elaborating. “Ultimately, an Afghanistan that does not respect the rights of its people, an Afghanistan that commits atrocities against its own people, would become a pariah state,” he said.

A senior State Department official noted India’s longstanding interest and substantial investment in Afghanistan, but declined to say what specific requests were made by either the U.S. or India during the visit.

The Taliban has advanced on provincial capitals in Afghanistan since the U.S. withdrew most of its remaining troops. Amid concerns about the survival of the Afghan government, WSJ’s Gerald F. Seib breaks down what the U.S. strategy in the region could look like. Photo illustration: Ang Li The Wall Street Journal Interactive Edition

Mr. Blinken’s visit came as the U.S. works to tighten security ties amid concern about Chinese influence in the region. A representative of the Taliban met with China’s foreign minister on Wednesday in the northeastern Chinese city of Tianjin.

Mr. Blinken met Wednesday with a representative of the Dalai Lama, in a move that is likely to anger Beijing.

The U.S. diplomat’s trip to India was one part of outreach to Asia by top Biden administration officials. Defense Secretary Lloyd Austin is in the midst of an Asian trip with stops in Singapore, the Philippines and Vietnam.

Mr. Blinken met with Indian Prime Minister Narendra Modi before departing on Wednesday. The diplomat then left for Kuwait, which U.S. officials hope to enlist in their effort to safeguard former interpreters and translators being evacuated from Afghanistan in the face of Taliban retaliation.

Diplomats from the U.S. and India gathered Wednesday at the state venue in New Delhi known as Hyderabad House.

Diplomats from the U.S. and India gathered Wednesday at the state venue in New Delhi known as Hyderabad House.

Photo: Jonathan Ernst/Associated Press

Besides the topic of Afghanistan, Messrs. Blinken and Jaishankar discussed joint efforts to distribute Covid-19 vaccines around the world and to address climate change by reducing emissions. In April, the two governments launched the U.S.-India Climate and Clean Energy Agenda 2030 Partnership, designed to meet the goals of the Paris Climate Agreement.

Mr. Blinken announced $25 million in U.S. assistance for supporting India’s vaccination efforts. The funding will contribute to saving lives by strengthening vaccine supply-chain logistics, addressing misinformation, vaccine hesitancy and helping to train more healthcare workers, he said.

Early this year, the U.S., Japan and Australia pledged more than $200 million to help Indian companies expand their capacities faster and add one billion doses to the global supply by the end of 2022.

During the bilateral meeting, the Indian side pressed for the gradual resumption of international travel, while maintaining health protocols, especially easing mobility of students, professionals and others, according to Indian officials. The two sides also discussed the scope and means to expand defense cooperation and boost bilateral trade and investments.

Write to Courtney McBride at courtney.mcbride@wsj.com and Rajesh Roy at rajesh.roy@wsj.com