Some of the challenges are self-inflicted, but a fresh set of court rulings questioning the president’s authority to enact tariffs hangs over his trade agenda.

China and the United States are accusing each other of reneging on their tariff truce as tensions rise over rare earths exports, computer chips and student visas.

China said on Monday that U.S. President Donald Trump's accusations that Beijing had violated the consensus reached in Geneva trade talks were "groundless", and promised to take forceful measures to safeguard its interests.

Karol Nawrocki, a right-winger backed by US President Donald Trump, has won Poland's presidential runoff, according to final results released on Monday - a result all but guaranteed to complicate relations with the European Union.

Karol Nawrocki, the conservative Trump-backed candidate in Poland's runoff election, has narrowly won the presidential race. Charles Kupchan, a senior fellow at the Council on Foreign Relations, breaks down how the election results may affect NATO and Poland's relationship with the European Union.

Poland has elected Karol Nawrocki, a nationalist conservative, as its next president — a win that signals a turn to the right in one of the European Union’s member states