US national security advisor reportedly held secret talks with top Russian officials to avert the use of nuclear weapons by the warring sides in Ukraine, according to a Wall Street Journal report.

US National Security Advisor Jake Sullivan has said that any individual or entity who supports the integration of eastern Ukrainian republics into Russia will face “severe” consequences.

Jake Sullivan said Washington's view was that the best way to support Ukraine was through "on-the-ground support in Ukraine."

The United States and its NATO allies say they have decided to increase their military presence in Europe in response to Russia's offensive against Ukraine, which is now in its fourth month.

The United States says North Korea could carry out nuclear tests or long-range missile tests, or both, during or after President Joe Biden’s visit to South Korea and Japan this week.

Saudi Arabia forced former Yemeni president Abd Rabbuh Mansur Hadi to delegate his self-proclaimed authority to a newly-established body after he held a private meeting with US National Security Advisor Jake Sullivan.

The White House warns that China will face costs if the country is seen as backing a potential Russian invasion of Ukraine.

US National Security Advisor Jake Sullivan censures the previous administration of president Donald Trump over its “disastrous” withdrawal from the 2015 Iran nuclear deal.

White House National Security Adviser Jake Sullivan has said that American intelligence agencies have concluded that Russian President Vladimir Putin is giving "serious consideration" to invade Ukraine.

Chinese Foreign Policy Adviser Yang Jiechi says confrontation between Beijing and Washington would damage both countries and the world.