The prime minister of Singapore joined President Barack Obama at the white House on Tuesday to celebrate the 50th anniversary of U.S. diplomatic relations with the Southeast Asian city-state, and he urged the United States to maintain its "indispensable role" in the Asia-Pacific region and ratify the Trans-Pacific Partnership (TPP) free-trade deal. Calling Singapore a "rock-solid" partner, Obama welcomed Prime Minister Lee Hsien Loong after an elaborate ceremony on the South Lawn of the White House. The two leaders were then meeting in the White House, and Lee also will be honored with a state dinner Tuesday evening. The U.S. president said they shared a "common vision of a peaceful and prosperous Asia-Pacific and a more secure world." He praised the tiny country's transformation into a leading economy over the last five decades. Singapore is one of the 12 countries in the TPP, but Lee's visit to Washington comes as opposition to the free-trade deal intensifies in the United States. Both Democrat Hillary Clinton and Republican Donald Trump oppose the agreement. Lee acknowledged that some Americans are anxious and frustrated with economic uncertainty and the uneven result of globalization and international trade, but said the United States is strengthened by its engagement in Asia. "Singapore fervently hopes that the U.S. will stay engaged and maintain its indispensable role in the Asia-Pacific. In particular, we hope, and I'm sure the president shares this hope, that Congress will ratify the TPP soon," Lee said, adding the trade pact will benefit U.S. workers and businesses and signal U.S. leadership in the Asia-Pacific region. Singapore, a city-state of 5.7 million people, is heavily dependent on international trade. In 2004, it became the first Asian country to reach a bilateral free-trade deal with the United States. Last year, the bilateral trade in goods totaled $47 billion, with the United States enjoying a $10 billion surplus. Singapore also is a strong advocate of the U.S. security role in Asia, although it maintains cordial ties with China, as well. Under Obama, the United States has deployed combat ships in Singapore and last December deployed a P-8 Poseidon spy airplane there for the first time, amid heightened tensions in the South China Sea.