HELSINKI, Finland — The top American military officer held talks Wednesday with his Russian counterpart as the United States struggles to secure basing rights and other counterterrorism support in countries bordering Afghanistan — an effort Moscow has opposed.

The daylong session in the Finland's capital between Gen. Mark Milley, chairman of the U.S. Joint Chiefs of Staff, and Gen. Valery Gerasimov, chief of the Russian General Staff, comes at a crucial time after the U.S. military withdrawal from Afghanistan.

Without troops on the ground, the U.S. needs to reach more basing, intelligence sharing and other agreements to help monitor al-Qaida and Islamic State militants in Afghanistan.

Russia's deputy foreign minister, Sergei Ryabkov, had said in July that Moscow warned the U.S. that any deployment of American troops in countries neighboring Afghanistan "is unacceptable." He said Russia told the U.S. "in a direct and straightforward way that it would change a lot of things not only in our perceptions of what's going on in that important region, but also in our relations with the United States."

Ryabkov also said that Russia had a "frank talk" with the Central Asian countries to warn them not to allow U.S. troops within their borders.

Milley declined to provide details of the meeting to reporters traveling with him to Helsinki. His spokesman, Col. Dave Butler, said the meeting would last all day and is "military focused."

"Both sides seek increased transparency to reduce misunderstanding and increase stability," Butler said. "The meeting is serious, both generals display mutual respect for each other though both have taken opportunity to quip or joke on occasion."

Both sides agreed not to disclose details of the talks, as has been the practice in previous meetings and calls.

But just a few days ago, Milley made it clear the basing issue was a key topic on his European trip, saying he discussed it with NATO counterparts when they met in Greece over the weekend.

Milley, U.S. Defense Secretary Lloyd Austin and American intelligence officials have warned that al-Qaida or IS could regenerate and pose a threat to the United States in one year to two years.

U.S. military leaders have said they can conduct counterterrorism surveillance and, if necessary, strikes in Afghanistan from military assets based in other countries. But they acknowledge that surveillance flights from bases in the Persian Gulf are long and provide limited time in the air over Afghanistan. So the U.S. and allies want basing agreements, overflight rights and increased intelligence-sharing with nations closer to Afghanistan, such as Uzbekistan, Kyrgyzstan or Tajikistan.

So far there are no indications of any progress. Moscow maintains a tight grip on the Central Asian nations and opposes a Western presence there. 

The U.S. used the Transit Center at Manas, in Krygyzstan, for a large part of the Afghanistan war, moving troops in and out of the war zone through that base. Under pressure from Russia and its allies, however, Krygyzstan insisted the U.S. vacate the base in 2014.

The U.S. also leased Karshi-Khanabad, known as K2, as a base in Uzbekistan for several years after the Afghanistan war began. Uzbekistan ordered the base closed in 2005 amid tensions with Washington, and the Defense Ministry reaffirmed in May that the country's constitution and military doctrine rule out the presence of foreign troops there.

It's unclear whether there is any potential for negotiations with the Russians to encourage them to lessen their objections to U.S. or allied presence in the region. But Russian officials also have expressed concern that the Taliban takeover could destabilize Central Asia, and they worry about a growing threat from IS.

Milley's meeting with Gerasimov, and broader discussions about counterterrorism this week, come on the heels of a deadly U.S. airstrike in Afghanistan in the final days of the chaotic evacuation of Americans, Afghans and others. The U.S. initially claimed the drone strike killed an Islamic extremist looking to attack the Kabul airport, but now says it was a mistake that killed 10 civilians, including seven children. 

The incident triggered questions about the future use of drone strikes to target terrorists in Afghanistan from beyond the country. But Gen. Frank McKenzie, head of U.S. Central Command, said that while that airstrike was a "tragic mistake" it was not comparable to future counterterror strikes.

Future strikes on insurgents deemed to pose a threat to America, McKenzie said, would be "done under different rules of engagement" and there would be more time to study the target.