Prime Minister Benjamin Netanyahu on Saturday endorsed US President Donald Trump’s plan to build a border wall, much to the chagrin of Mexico.

“The Mexican Secretariat of Foreign Affairs has expressed to the Israeli government through its ambassador in the Mexico City its deepest surprise, rejection and disappointment by the statement made by Prime Minister Netanyahu,” read a statement released by Mexico’s government.

“Mexico is Israel’s friend and Israeli prime minister should behave himself in regard to Mexico properly,” it continued.

Hours earlier, Netanyahu had posted to Twitter: “President Trump is right. I built a wall along Israel’s southern border. It stopped all illegal immigration. Great success. Great idea”

President Trump is right. I built a wall along Israel's southern border. It stopped all illegal immigration. Great success. Great idea

— Benjamin Netanyahu (@netanyahu) January 28, 2017

Israel has struggled to deal with a flood of refugees and other African migrants crossing its southern border in recent years.

Long before that, the largely unfenced frontier was crossed almost with impunity by smugglers and drug traffickers.