Cuomo, in a speech to supporters, said he hopes to "vindicate" the trust New Yorkers have placed in him by electing him to another four-year term.
In the one of the most eagerly-anticipated U.S. midterm elections in recent memory, the Democrats were on course to gain the 23 seats they needed to capture the Republican-held House. Neither could actually be removed from office without a two-thirds Senate vote, but a Democrat House could dominate months of congressional business and news headlines with investigations and proceedings.
See the results below for all of the House and Senate races in this interactive graphic, which we'll be updating live throughout the night as they come in.
"Lavrov also reiterated Moscow's position that it is not meddling in USA elections".
Democratic gains included several suburban districts eyed for turnover because they were won by Hillary Clinton, including seats outside Washington, Philadelphia, Miami and Denver.
Some analysts have said that if the Democrats win control of the House and resist President Trump, it could end up helping Trump's re-election chances in 2020.
Every seat in the House, 35 seats in the 100-member Senate and 36 of the 50 state governorships were up for grabs.
Democrats got good news early, as a number of early seats in Virginia and Kentucky flipped blue on Tuesday night.
But Republicans struck back in the 100-member Senate, where they ousted at least two Democrats, in IN and North Dakota, and held on to at-risk seats in Tennessee and Texas.
Some of the biggest Democratic stars of the campaign season were struggling. They also suffered a stinging loss in Florida, where Trump-backed Republican Ron DeSantis ended Democrat Andrew Gillum's bid to become the state's first African-American governor.
The surviving Republican members in the House, too, will have little interest in cooperating with the new Democratic majority, leaving Republican congressional power focussed in the Senate and the government largely gridlocked. Democrat state legislator Laura Kelly will be that state's next governor. Still, Republican voters tended to be overwhelmingly supportive of the president.
While Democrats need to win eight of 30 toss-up races to win the majority, Republicans need 23 to win. According to VoteCast, half of voters said the tumultuous process was very important to their vote and they broke for the Democratic House candidate.
Allan, the Indianapolis truck driver, said he likes how Trump is leading the country, particularly when it comes to immigration and foreign policy.
In total, Trump had held 26 rallies since October, embracing Democrats' attempts to make the election a referendum on his agenda.
For the Democrats taking control of the House gives them an opportunity to be more assertive in the Congress and prevent Trump for achieving his legislative agenda.
The loss of power will test Trump's political hold on House Republicans, most of whom had pledged their support for him lest they face the wrath of the party's core supporters, who remain in his corner.
With divided leadership in Congress and a president who has taken an expansive view of executive power, Washington could be in store for even deeper political polarization and legislative gridlock.
Democrats faced a far more hard challenge in the Senate, where they were nearly exclusively on defence in rural states where Mr Trump remains popular.