China and Belarus started joint military exercises on Monday, the Belarusian and Chinese defence ministries said, holding the drills just few miles (km) from the border of NATO-member Poland and kicking them off on the eve of the alliance's summit.

"Events taking place in the world are alarming, the situation is uneasy, therefore we are going to practice new forms and methods of performing tactical tasks," Major General Vadim Denisenko, chief of Belarusian special operations command, was cited by the Belarusian defence ministry as saying in a post on the Telegram messaging app.

The manoeuvres, codenamed Falcon Assault, will go until July 19 and are taking place at a training ground near the city of Brest, the ministry said. Brest, in southwest Belarus, lies on the border with Poland.

Leaders of NATO's 32 member countries meet on Tuesday in Washington for a summit where further military and financial support for Ukraine will be high on the agenda.

Belarus allowed Russia to use its territory as one of the launchpads for Moscow's full-scale invasion of Ukraine in 2022.

As part of the "anti-terrorist exercises", military personnel of both countries will work out issues of night landing, overcoming water barriers, and conducting operations in a populated area, the Belarusian defence ministry said in its statement.

The ministry also posted a series of photos on Telegram, showing over the weekend Chinese troops disembarking from a plane and offloading equipment. In Monday posts it showed the troops marching at a training ground. It was not clear how many troops were involved in the drills.

The Chinese defence ministry said in a statement on Monday that Belarus held a "a grand welcome ceremony" for the Chinese troops who arrived in Belarus on July 6, according to a statement published in English on the ministry's website.

"The joint training aims to enhance the coordination capabilities of the participating troops, and deepen practical cooperation between the two armies," the ministry said in the statement.

In an unrelated post on Telegram, the Belarusian defence ministry said on Monday that the size of NATO forces on the border with Belarus is rapidly growing, which leads to increased tension in the region.

"Our country is taking all possible measures to prevent escalation. However, if someone crosses our borders, the reaction will be harsh," it said in the post.