Moscow on Tuesday denounced a potential visit by US House Speaker Nancy Pelosi to Taiwan as a provocation, expressing full solidarity with ally China.

"What is connected with this tour and a possible visit to Taiwan is a pure provocation," Kremlin spokesman Dmitry Peskov told reporters.

He said the potential visit was leading to an "increase in tension" in the region and accused Washington of choosing "the path of confrontation".

"We want to emphasise once again that we are absolutely in solidarity with China, its attitude towards the problem is understandable and absolutely justified."

Russian foreign ministry spokeswoman Maria Zakharova also accused the United States of being provocative over the potential visit.

"Washington is bringing destabilisation to the world. Not a single resolved conflict in recent decades, but many provoked ones," she said on social media.

Faced with unprecedented sanctions and international isolation over its military campaign in pro-Western Ukraine, Russia has sought closer ties with China and expressed solidarity with Beijing over Taiwan.

China considers Taiwan its territory and has indicated through repeated warnings that it would view a visit by Pelosi as a major provocation.

American officials often make discreet visits to Taiwan to show support, but Pelosi -- who is currently on a tour of several Asian countries -- would be a higher-profile visitor than any in recent history.

Democratic Taiwan lives under constant threat of being seized by China.

Moscow's assault on Ukraine has heightened fears that Beijing might similarly follow through on threats to annex its much smaller and outgunned neighbour.