Taiwan accused the Chinese army of simulating an attack on its main island Saturday, as Beijing doubled down on its retaliation for U.S. House Speaker Nancy Pelosi's visit to Taipei after announcing a suspension of cooperation with Washington on key issues.

Ways to halt the war in Ukraine and the possible launch of a new conflict in Syria are expected to dominate talks on Friday between Russian President Vladimir Putin and Turkish counterpart Recep Tayyip Erdogan.

The Turkish leader was riding high from the diplomatic success of helping orchestrate the resumption of Ukrainian grain shipments across the Black Sea when he took most of his top ministers to Sochi for his second talks with Putin in 17 days.

China on Friday said it is canceling or suspending dialogue with the United States on a range of issues from climate change to military relations and anti-drug efforts in retaliation for a visit this week to Taiwan by U.S. House Speaker Nancy Pelosi.

The measures, which come amid cratering relations between Beijing and Washington, are the latest in a promised series of steps intended to punish the U.S. for allowing the visit to the island it claims as its own territory, to be annexed by force if necessary. China on Thursday launched threatening military exercises in six zones just off Taiwan's coasts that it says will run through Sunday.

China will not isolate Taiwan by preventing U.S. officials from traveling there, U.S. House Speaker Nancy Pelosi said Friday in Tokyo, wrapping up her Asia tour highlighted by a visit to Taipei that infuriated China.

The Chinese have tried to isolate Taiwan, Pelosi said, including most recently by preventing the self-governing island from joining the World Health Organization.

Russia said Friday it was ready to discuss a prisoner swap with Washington at the presidential level, a day after the drug conviction of U.S. basketball star Brittney Griner. 

Despite tensions soaring between Russia and the U.S. since the launch of Moscow's military intervention in Ukraine, the former Cold War rivals appeared to be edging closer to a new prisoner exchange.

Mourners have poured out onto the streets of Tehran to pay their respects to several Iranian officers killed in Syria, a testament to the human cost of Iran's involvement in the civil war and a public display of nationalist fervor as nuclear talks resume in Vienna.

The remains of the paramilitary Revolutionary Guard members were recently recovered in Khan Tuman, a village 9 miles (about 15 kilometers) south of Aleppo, Syria's largest city that was for years the war's most important front line.

U.S. Secretary of State Antony Blinken said Friday that China's military exercises aimed at Taiwan including missiles fired into Japan's exclusive economic zone represent a "significant escalation."

China's military drills were launched following a visit earlier this week by U.S. House Speaker Nancy Pelosi to Taiwan that infuriated Beijing.

Ukrainian forces are violating international law and endangering civilians by establishing bases in residential areas, including in schools and hospitals, Amnesty International said Thursday.

Ballistic missiles fired by China are believed to have landed in Japan's exclusive economic zone for the first time, Tokyo's defense minister said Thursday.

After her high-profile trip to Taiwan, U.S. House Speaker Nancy Pelosi was in South Korea Thursday where her agenda included a visit to the heavily fortified Demilitarized Zone (DMZ) -- but not a meeting with the country's president.