MOSCOW, Oct 12 — Tuesday talks in Moscow between Russian and US officials to resolve a diplomatic standoff ended without any breakthroughs, but were still "useful”, Moscow’s deputy foreign minister said.

The discussions held behind closed doors saw Russia’s Deputy Foreign Minister Sergei Ryabkov and US Under Secretary of State Victoria Nuland discuss a long-running row over embassy staffing limits, among other issues.

The meeting comes with Washington’s ties with Moscow under particular strain over a long list of disagreements including the conflict in Ukraine, which Ryabkov said was not discussed.

He said the two officials had failed to make progress on the functioning of diplomatic missions including visas and rotation of personnel.

"Americans are not heeding our logic or our demands,” state news agency RIA Novosti quoted Ryabkov as saying. "At the same time the talks were useful.”

He also warned that a lack of progress on core disagreements raised the possibility of new areas of conflict.

"There is very little progress when it comes to the substantive part of the problems that exist,” news agency Interfax quoted Ryabkov as saying. "There is a risk of new aggravations.”

Ties between the former Cold War enemies rapidly deteriorated after Joe Biden increased pressure on the Kremlin since becoming US president in January.

As part of tit-for-tat sanctions, Russia earlier this year prohibited the US embassy in Moscow from employing foreign nationals and formally designated the United States as an "unfriendly state.” 

Nuland, who is on a three-day visit to Russia, arrived yesterday. She is set to meet with President Vladimir Putin’s foreign policy advisor Yury Ushakov during her visit, the Kremlin said.

Nuland was allowed to travel to Russia despite previously having been placed on a sanctions list.

In exchange, Washington issued a US visa to a representative of the Russian foreign ministry. — AFP