The joint "antiterrorist" exercises on Russian ally Belarus's soil near the Polish border come as NATO leaders gather for a summit in Washington, with the war in nearby Ukraine high on their agenda.

With relations between NATO on the one hand and China and Russia on the other at a low ebb, analysts believe that Beijing wanted to send the alliance a warning message with the timing of the drills.

Sino-Belarusian exercises have taken place before, but this is the first time since Russia invaded neighbouring Ukraine, a NATO ally, in February 2022.

The exercises began July 8 in Brest, a city right on the border with Poland, according to a statement issued on Wednesday by the Chinese defence ministry.

The statement said the manoeuvres will last until mid-July, but did not give the exact number of Chinese soldiers involved.

Both sides are working to "improve combat techniques and deepen cooperation and communication between the two armies", the statement added.

Chinese diplomatic officials insisted that the exercises were "not aimed at any country in particular".

But Poland's defence ministry slammed the timing of the exercises.

It warned of "the risk of the operations in question being used for disinformation and propaganda purposes... to coincide with the NATO summit".

However small in scale, the exercises still involve China deploying troops on NATO's doorstep, and to a country Russia used as a launchpad for its invasion of Ukraine.

And the exercises come as Beijing, one of Moscow's key partners, is also experiencing increasingly tense relations with NATO.

- Strategic signal -

Analysts believe that date and location of the exercises were not chosen by chance, arguing that China wanted to send NATO a message.

"Multilateral exercises are often used to send political signals," Kelly Grieco of the Stimson Center foreign policy and defence think tank told AFP.

Indeed, she argues that when it comes to military drills, "it's much more about political signal more than for the exercise itself".

She points out that China had already carried out anti-terrorism exercises in Belarus four times between 2011 and 2018, but had not done so since.

That they are taking place "that close to the border is part of the signalling" too, she added.

Countries often organise their joint exercises to coincide with developments abroad -- not least of them China, added Alice Ekman, senior analyst for Asia at the European Union Institute for Security Studies (EUISS).

"In April 2023, the Chinese held exercises with Russia in the East China Sea, close to Japanese islands, on the eve of a trilateral US-Japan-South Korea summit to signal their opposition to such a summit being held," Ekman told AFP.

Similarly, China staged military manoeuvres in the South China Sea in May 2024 as the US-Japan-Philippines-Australia meeting was in full swing, she added.

As well as moving closer to Russia, China is becoming increasingly hostile to NATO.

It accuses NATO of working to contain China at Washington's instigation, with Beijing worried about the alliance's expanding role in the Asia-Pacific region.

Moreover, China has never forgiven the bombing of its embassy in Belgrade by a NATO plane in 1999.

It also believes that the alliance has already overstepped its geographical sphere of influence in Iraq, Libya and Afghanistan.

NATO is perceived by China as "clearly hostile for historical reasons", Ekman said.

But those reasons were becoming "increasingly strategic as the threat from China becomes an integral part of the organisation's strategic thinking", she added.