Donald Trump vowed to usher in a new era of American greatness, minutes after he was sworn in as president for the second time to complete an extraordinary political comeback following two assassination attempts, a felony conviction and an indictment for attempting to overturn his 2020 election loss.  "The golden age of America begins right now," he said.

Donald Trump took the oath of office to "preserve, protect and defend" the U.S. Constitution at 12:01 p.m. ET (1701 GMT) inside the U.S. Capitol, administered by Chief Justice John Roberts, according to . His vice president, JD Vance, was sworn in just before him.

NBC News says Trump, in a relatively sedate and focused style, spoke for nearly 40 minutes in the Capitol rotunda after he was sworn in as the United States' 47th president.  In a second set of freestyle remarks in the Capitol's Emancipation Hall, Trump attacked political adversaries, called the 2020 election "totally rigged" and blamed former House Speaker Nancy Pelosi, D-Calif., for his supporters' attacking the building on January 6, 2021, in a futile effort to overturn the 2020 election.  In the evening, at a rally in Washington's Capital One Arena, Trump went further in assailing Democrats and praising January 6 “hostages” who were convicted at trial.

Proclaiming that a "golden age begins right now", Mr. Trump also said he would rename the Gulf of Mexico the "Gulf of America" and take back the Panama Canal in his inauguration address, Sky News reports.

“I'm going to put America first...  The scales of justice will be rebalanced,” Trump said.  “From this moment on, America's decline is over.”

In his executive orders, he “declared a national emergency" at the southern border with Mexico as well as a "national energy emergency”.

He reportedly granted pardons and commuted sentences for people related to the January 6 riots and targeted automatic citizenship for US-born children of illegal immigrants;

The following is an international reaction to Trump's inauguration.

According to Reuters, Volodymyr Zelenskiy of Ukraine said, “President Trump is always decisive, and the peace through strength policy he announced provides an opportunity to strengthen American leadership and achieve a long-term and just peace, which is the top priority.”

Israel Prime Minister Benjamin Netanyahu was cited as saying, “I believe that working together again we will raise the U.S.-Israel alliance to even greater heights.”

“Since Mr. Trump repeatedly said he would end the Russia-Ukraine war, we as Turkiye will do whatever necessary in this regard.  We need to resolve this issue as soon as possible.  This issue will be on our agenda with our talks with Mr. Trump, and we would take our steps accordingly.  I wish Mr. Trump's second term would bring good for all humanity," President of Turkiye Tayyo Erdogan said, according to Reuters.

German Chancellor Olaf Scholz was cites as saying, “Today President Donald Trump takes office. Congratulations! The U.S. is our closest ally and the aim of our policy is always a good transatlantic relationship. The EU, with 27 members and more than 400 million people, is a strong union.”

"Best wishes President Donald Trump, for your tenure as 47th President of the United States.  The EU looks forward to working closely with you to tackle global challenges. Together, our societies can achieve greater prosperity and strengthen their common security. This is the enduring strength of the transatlantic partnership." Ursula von der Leyen, European Commission President, said, according to Reuters.   

China’s State Council says upon invitation, Chinese Vice President Han Zheng attended the inauguration ceremony of U.S. President Donald Trump.  He reportedly noted that Xi recently had an important phone call with Trump, during which the two leaders have reached many important consensuses on the development of China-U.S. relations in the next stage.  China is ready to work with the United States to adhere to the strategic guidance of the head-of-state diplomacy and follow through on the important consensus reached between Xi and Trump, so as to push for the steady, healthy and sustainable development of bilateral ties, Han said.

Reuters says Russian President Vladimir Putin congratulated U.S. President-elect Donald Trump on taking office hours before Trump's inauguration in Washington and said he was open to dialogue with the new U.S. administration on Ukraine and nuclear arms.

Iran International reports that the administration of Iran's President Masoud Pezeshkian has hinted at willingness to engage with US under Donald Trump and to open Iranian markets to US companies.  In a recent interview with NBC, President Pezeshkian reportedly stressed Tehran's readiness for dialogue with the US, while also stating that the Islamic Republic had no intentions of assassinating Donald Trump over the 2020 killing of the IRGC's Qasem Soleimani in Baghdad.  A senior aide to Pezeshkian, Ali Abdolalizadeh, was cited as claiming on Saturday that an agreement with the Trump administration could be reached within two or three months.