Hackers accessed the European Union’s diplomatic communications network for years, downloading cables that revealed concerns about the Trump administration, struggles to deal with Russia and Chin, and the risk of Iran reviving its nuclear programme, the New York Times has reported.

More than 1,100 cables were supplied to the Times by the security firm Area 1 after it discovered the breach, the newspaper said, adding that Area 1 investigators believed the hackers worked for the Chinese People’s Liberation Army.

The cables include memorandums of conversations with leaders in Saudi Arabia, Israel and other countries that were shared across the EU, according to the report.

In one cable, the Times said, European diplomats described a meeting between the US president, Donald Trump, and his Russian counterpart, Vladimir Putin, in Finland as “successful (at least for Putin)”.

Another, written after a 16 July meeting, gave a detailed report and analysis of talks between European officials and the Chinese president, Xi Jinping, who was quoted comparing Trump’s “bullying” of Beijing to a “no-rules freestyle boxing match”.

A third, from 7 March, shows Caroline Vicini, the deputy head of the EU mission in Washington, recommending that the trade bloc’s diplomats describe the US as “our most important partner” even as it challenged Trump “in areas where we disagreed with the US (eg, on climate, trade, Iran nuclear deal)”.

The hackers also infiltrated the networks of the UN, the American Federation of Labor and Congress of Industrial Organizations (AFL-CIO), and ministries of foreign affairs and finance worldwide, the report added.