U.S. President Donald Trump and First Lady Melania Trump meet with Spain's King Felipe VI and Queen Letizia in the Oval Office of the White House in Washington, D.C. on June 19, 2018. (Xinhua/AFP)

WASHINGTON, June 20 (Xinhua) -- The White House said here Wednesday that President Donald Trump and visiting Spanish King Felipe VI discussed bilateral concerns on security, trade and energy.

In a statement, the White House said Trump and his wife Melania welcomed Felipe VI and Queen Letizia to the White House on Tuesday, "culminating in the royal family's tour across the country."

While reaffirming the decades-long bilateral military alliance and commitment to the North Atlantic Treaty Organization, the two leaders discussed strengthening economic and security ties, balancing transatlantic trade, and diversifying Europe's sources of energy.

Trump also expressed support for a strong and united Spain.

According to emails of White House correspondents, the king and queen were about to wrap up their five-day visit to the United States. They had visited New Orleans and San Antonio to mark the 300th anniversary of those cities, which are blessed with a rich Spanish heritage.

Spain and the European Union have recently been concerned about the Trump administration's tariffs on steel and aluminum. The European nation was also worried about the United States' latest announcement to slap tariffs on Spanish black olives.

Immigration policy has also been a major concern for the United States and Spain. Over 600 migrants rescued in the Mediterranean Sea have arrived in Spain after being turned away by Italy and Malta.