Donald Trump goes on New Year's Day Twitter offensive with attacks on Iran and Pakistan

Having hosted a New Year's Eve Party, US President Donald Trump was up early at his winter home in Palm Beach, Florida, and ready to kick off 2018 with a fresh batch of acerbic tweets.

Reacting to the ongoing protests in Iran, in which now at least 12 people have been killed in clashes with security services, Trump said Iran is "failing at every level." He voiced his support for the protesters there, saying it is "TIME FOR CHANGE."

Trump tweeted: "Iran is failing at every level despite the terrible deal made with them by the Obama Administration. The great Iranian people have been repressed for many years. They are hungry for food & for freedom. Along with human rights, the wealth of Iran is being looted. TIME FOR CHANGE!"

The protests began Thursday in Mashhad over economic issues and have since expanded to several cities. Hundreds of people have been arrested.

While some have shared Trump's tweets, many in Iran distrust him as he's refused to re-certify the nuclear deal and because his travel bans have blocked Iranians from getting U.S. visas.

Trump had earlier sent an angry, early morning tweet criticizing Pakistan.

Trump tweeted: "The United States has foolishly given Pakistan more than 33 billion dollars in aid over the last 15 years, and they have given us nothing but lies & deceit, thinking of our leaders as fools. They give safe haven to the terrorists we hunt in Afghanistan, with little help. No more!"

It was not immediately clear why Trump opted to tweet on Pakistan. The U.S. has long accused Istanbul of allowing militants to operate relatively freely in Pakistan's border regions to carry out operations in neighbouring Afghanistan.

The previous evening, bidding farewell to 2017 with a lavish party at his private club, President Donald Trump predicted 2018 will be a "tremendous year."

Trump said Sunday that the stock market will continue to rise and that companies are going to continue to come into the U.S., at "a rapid clip." He also cited several accomplishments, including the tax overhaul, opening the Arctic National Wildlife Refuge to oil drilling, and repealing the individual mandate from the national health care law.

"It will be a fantastic 2018," a tuxedoed Trump said, as he entered the gilded ballroom at Mar-a-Lago, accompanied by first lady Melania Trump and son Barron.