April 3 (Reuters) - Nissan Motor ( NSANF ) said on Thursday it will not take new orders from the U.S. for two Mexican-built Infiniti SUVs, following auto tariffs levied by President Donald Trump, in a drastic scale-back of its operations at a joint venture plant.

The Japanese automaker said it would now maintain two shifts of production of the Rogue SUV at its Smyrna, Tennessee, plant after announcing in January it would end one of the two shifts this month.

Nissan ( NSANF ) will not accept any additional orders of the Infiniti QX50 and QX55 SUVs for the U.S. market produced at the COMPAS plant it has run together with Mercedes-Benz in Mexico. Nissan ( NSANF ) said production is expected to continue for those models sold in other markets.

It remained unclear how much of the production is sold in other markets. The two Infiniti models have only been exported from Mexico to the U.S., according to data from Mexico's national statistics agency.

A Japan-based Nissan ( NSANF ) spokesperson said on Saturday the models are produced for and exported to markets such as Mexico, Panama, the Middle East and Canada, without providing details on its production plans for the vehicles.

Trump's 25% global car and truck tariffs took effect on Thursday.

Nissan ( NSANF ) has been struggling in the U.S. due to an ageing line-up and a lack of hybrid models. It is particularly exposed to the new tariffs as it exports the biggest number of cars from Mexico to the U.S. of any Japanese automaker.

Nissan's ( NSANF ) troubles led it to slash its profit forecast three times in the financial year just ended and saw its debt downgraded to "junk" status.

Its new chief executive, 46-year-old Ivan Espinosa, a Mexican national who previously was its planning boss, has pledged to drastically cut the time the automaker needs to develop new cars.

Mercedes-Benz manufactures the GLB SUV at the COMPAS plant. (Reporting by David Shepardson and Daniel Leussink; Editing by Chris Reese and Muralikumar Anantharaman)