A nuclear weapons control treaty signed between the US and Russia -- the two nations that possess the vast majority of the world's nuclear warheads -- is set to expire on Thursday.
The Strategic Arms Reduction Treaty, or New START, is the only nuclear disarmament pact that binds the US and Russia.
It caps the number of deployed strategic nuclear warheads for the United States and Russia at 1,550 and limits the number of deployed intercontinental ballistic missiles, submarine-launched ballistic missiles and strategic bombers to no more than 800.
Russian President Vladimir Putin in September effectively proposed extending the treaty by another year.
US media have reported that President Donald Trump indicated in January that he may let the treaty expire, saying, "If it expires, it expires."
Unless a new agreement is reached, the two nations, which together hold nearly 90 percent of the world's nuclear weapons stockpile, would face no limits on their nuclear capabilities.
Trump has also insisted on the need for a new framework that includes China, but no concrete steps have been taken by the countries involved.
US Secretary of State Marco Rubio told reporters on Wednesday that any future nuclear deal with Russia must include China.
He said that achieving meaningful arms control in the 21st century would be "impossible" without Beijing's participation.
The treaty's expiry comes as the US, Russia and China continue to develop new missiles capable of carrying nuclear warheads and modernize their armed forces.
Concerns are growing that this could accelerate a new global nuclear arms race.

Quiz 1:
What is the name of the treaty set to expire on Thursday?
A. The Global Arms Control Treaty
B. The Strategic Arms Reduction Treaty (New START)
C. The US-Russia Nuclear Disarmament Pact
D. The Beijing Arms Limitation Agreement

Quiz 2:
According to the article, what does the New START treaty currently limit for the US and Russia?
A. The total number of all nuclear weapons.
B. The number of nuclear power plants.
C. The number of deployed strategic nuclear warheads to 1,550.
D. The number of strategic bombers to 1,550.

Quiz 3:
What is a major condition that US Secretary of State Marco Rubio believes is necessary for a future nuclear deal with Russia?
A. The inclusion of China in the agreement
B. The immediate dismantling of all nuclear weapons
C. The US reducing its nuclear arsenal by 50%
D. Russia paying reparations for past actions



[Answer block]
Answers:
Quiz 1: B
Quiz 2: C
Quiz 3: A