US President Donald Trump (L) and North Korea leader Kim Jong Un. Image: Reuters/Files

WASHINGTON: Two senior Democratic senators asked the country's intelligence chief Thursday to assess the national security risks of President Donald Trump's tweets on North Korea.

Senators Martin Heinrich and Ron Wyden asked the Director of National Intelligence, Daniel Coats, to "assess the risk to the United States and to US interests and personnel" arising from a tweet Trump posted on January 2.

In that tweet, Trump made a veiled threat to North Korean leader Kim Jong-Un, who, a day earlier, opened the New Year with his own defiant statement calling to speed up the deployment of nuclear weapons.

"North Korean Leader Kim Jong Un just stated that the 'Nuclear Button is on his desk at all times.' Will someone from his depleted and food starved regime please inform him that I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works!" Trump wrote.

Heinrich and Wyden, both members of the Senate Intelligence Committee, said they would like the intelligence community to assess the impact of Trump's tweets on Washington's credibility.

US nuclear button 'much bigger' than N Korea's: Trump

Trump's message came after Kim used his annual New Year address to warn he has a 'nuclear button' on his table

"We request that the assessment address the likely North Korean response to the President's January 2 tweet and the President's other threatening tweets and statements and whether this rhetoric serves as a deterrent or a provocation."

Kim's New Year statement extended an olive branch to Seoul, which in the subsequent days led to a renewal of direct contacts, reopening a cross-border hotline and a proposal to hold bilateral talks on January 9.

On Thursday Trump turned to Twitter again to claim credit.

"With all of the failed 'experts' weighing in, does anybody really believe that talks and dialogue would be going on between North and South Korea right now if I wasn't firm, strong and willing to commit our total 'might' against the North. Fools, but talks are a good thing!"