By Sukriti Gupta and Sanchayaita Roy (Reuters) -European shares were mixed on Tuesday as investors assessed the latest phase of U.S. President Donald Trump's tariff rollout, which included new proposals for several countries and a new deadline for trade deals.

The commercial relationship between the United States and the European Union, described by the European Commission as 'the most important trade relationship in the world,' is under significant strain due to President Donald Trump's tariff policy.

After the S&P 500 roared to all-time highs in June, investors are taking a cautious approach with the threat of tariffs looming.

U.S. President Donald Trump on Tuesday said he would impose a 50% tariff on imported copper and soon introduce long-threatened levies on semiconductors and pharmaceuticals, broadening his trade war that has rattled markets worldwide.

President Donald Trump said on Tuesday he will announce a 50% tariff on copper later in the day, aiming to boost U.S. production of a metal critical to electric vehicles, military hardware, the power grid and many consumer goods.

Copper entering the US from other countries is set to face a new tax of 50%, President Donald Trump has said. The decision carries through on tariff threats he made earlier this year, when he ordered an investigation into how imports of the metal were affecting national security.